What information do I need to calculate how long a battery will last?

In our article discussing Ah (ampere-hours) and Wh (watt-hours), we got a ton of questions about the longevity of batteries. The question “How long does a battery last?” was a predominant one. To help everybody trying to calculate how long will a battery last, we have created a Battery Life Calculator.
It’s quite useful knowing when a battery will die on us. Example: If we go camping and depend on batteries for all our power needs, and we have no other means of generating electricity.
Before we check out the Battery Life Calculator, let’s note that figuring out how long will a battery last is pretty simple in theory (in practice, it’s actually quite difficult). We use this equation for battery drain time:
Battery Life (in hours) = Battery Capacity (in Ah) / Load Current (in A)
What does ah mean on a battery? It just means amp-hours. 1 Ah is a current of 1 amp running for 1 hour.
Example: How long will a 100 Ah (amp-hour) battery last if we hook it up to a 1 Ah electric device? Well, battery capacity = 100 Ah, load current = 1 A, thus such a battery will last for 100 Ah / 1 A = 100 hours.
Basically, a 100 Ah battery means that such a battery can provide 100 A of current for 1 hour. It can also provide 1 A current for 100 hours. Or 0.1 A or 100 mA for 1000 hours.
It seems quite simple, right?
If you have 100 capacity units (100 Ah) and you connect it to a device that requires 1 capacity unit (1 A) every hour, it will drain the battery in precisely 100 hours.
Why Calculating The Battery Life Is Not Exactly Easy
Here’s the deal:
In practice, we only need two numbers to calculate when the battery will die on us. These are:
- Battery capacity (in Ah). This one is pretty easy to get; it’s written right on the battery. Typical AA battery has 2.5 Ah or 2500 mAh (milli-amp-hours) capacity, AAA battery has 1 Ah capacity, laptop battery has 2 Ah to 6 Ah, 100 Ah battery has Ah capacity, and so on. You can read more about battery capacities here.
- Load Current or Amp Draw (in A).

Calculating how long a battery will last at a given rate of discharge is not as simple as "amp-hours" - battery capacity decreases as the rate of discharge increases. For this reason, battery manufacturers prefer to rate their batteries at very low rates of discharge, as they last longer and get higher ratings that way. That is fine if you're building a low-power application, but if your contraption really "sucks juice", you won't be getting the amp-hours you paid for.
The formula for calculating how long a battery will really last has the charming name of "Peukert's Formula". It is...
T = C / In
You can see from the graph that a battery with a Peukert's number of 1.3 has half the capacity of a battery with a Peukert's number of 1.1 at a discharge rate of 25 amps, even though they both have the same theoretical capacity (and are probably rated the same by the manufacturers).
Here is a little calculator to play with.
Batteries don't last forever - their lifetimes are measured in cycles, or how many times they can be discharged and recharged before they will no longer take a full charge. The depth of discharge (D.O.D.) has a major effect on the life expectancy of a battery - discharging only 80% of the total capacity of the battery will typically get you 25% more cycles than total discharges, and discharging to only 20% will make the battery last essentially forever. Car batteries, however, have to be treated differently - they're not designed to discharge even 20%, and will be damaged if they're deeply discharged. A "deep cycle" battery, on the other hand, can typically survive 400 full discharges.
Very often, one battery won't do the trick - or more likely, you don't have the one that will do the trick, so you're stuck with multiple small batteries.
Hooking batteries in parallel will give you the same voltage as a single battery, but with a Ah and current carrying capacity equal to the sum of the capacities of all the batteries. For example, three 12v 20 Ah batteries in parallel will give you 12v 60 Ah. If each battery could put out 200 amps max, three in parallel could put out 600 amps max.

Power = Watts
Higher voltage means more power, right? Not quite…
Power is measured in watts (W), and watts are calculated by multiplying voltage (V) by the current (amps, A). It’s possible to get the same power, for example, from an 18V battery and a 54V battery—but the 54V pack will do it with 2/3 less amps than its little brother.
Runtime = Watt-hours
Watt-hours (Wh) simply refers to how many watts a battery can put out for 1 hour. Just like power, watt-hours is calculated by multiplying voltage by the rated amp-hours (Ah) of the pack. This will be how you can calculate run-time of your tool.
What is “Nominal”?
The battery packs that you use on your tools are made up of many cylindrical cells, similar in shape to the AAs in your TV remote but much bigger and packed with a lithium-ion chemical cocktail to give them much higher energy density instead of the low energy, but very cheap, alkaline type that you buy in the check-out line of your local supermarket.
Battery cells are chemistry in a can, not perfectly identical production machines. The term nominal is an industry standard used by manufacturers of lithium-ion battery cells to rate the approximate mid-point voltage of their batteries. Nominal voltage ratings are, essentially, the average rating of the cells produced with a certain chemistry. In general, all commonly used lithium-ion battery cells are 3.6V nominal voltage. Beyond voltage, there are many options for cells with different amp-hour ratings as well as different maximum discharge current ratings, depending on how long a manufacturer wants the battery to last on a specific tool and how fast the pack is able to use its energy (i.e. higher power) during operation, respectively. Not all cells are created equal.
You are surely more familiar with the battery packs itself than the actual cells that these packs are made up of. Battery packs are made of stacks of cells assembled in tight clusters and connected in different series or parallel configurations to produce some combination of higher voltage or higher amp-hours, depending on the design and application of the tool it is intended to power.
When assembled in series, cell voltage (3.6V nominal) is multiplied by the number of cells in the series.

This is the tricky one; and the whole reason why calculating battery lifetime is difficult. Load current determines how fast the electrical capacity will be drawn from the battery, and depends on the power of the unit attached to it. 1000 W air conditioner, for example, will have a 10 times as big a load current than a 100 W personal evaporative cooler.
If you get these two numbers, you just divide battery capacity with load current and get how many hours a battery will last.
The problem is that questions about battery life are not posed in this way:
“I have a 100 Ah battery and want to run a camping light with a load current of 1 Ah with it. How long before the battery runs out?”
Most of us deal with watts (W). We don’t know what the load current of a 100 W light is. We just know that it’s a 100 W light, right. That’s why most questions about how long batteries last go along these lines:
“I have a 100 Ah battery and want to run a 100 W camping light with it. How long before the battery runs out?”
To adequately calculate the battery lifespan, we need to transform that 100 W into Ah. Here the voltage (V) plays the key role.
We want everybody to be able to determine how long will their battery life last. That’s why we feature 3 key sections that will help you out to do just that:
- How to calculate the load current of any device. We start with knowing wattage (W) and voltage (V), and we’ll be able to calculate how many amps (A) does such a device needs to run. If you can calculate the amp draw (or load current), you can use the Battery Life Calculator.
- Battery Life Calculator. You just input the battery capacity that’s written on your battery (in Ah) and the calculated amp draw (load current), and the calculator will tell you how many hours the battery will last.
Let’s start with the basics: How to get from watts to amps?
How To Calculate Load Current (Amps) From Wattage?
Imagine a simple enough scenario. You have a big 200 Ah lithium battery and want to run a small 800 W portable air conditioner with it. How long can you run such an AC before the battery dies out?
Well, we already know that we need 2 numbers:
- Battery capacity.

Hence, the final version of the battery capacity formula looks like this:
E = V * Q
energy = voltage * battery capacity
- energy – It’s the energy stored in a battery, expressed in watt-hours (Wh);
- voltage – It’s the voltage of the battery;
- battery capacity – It’s measured in amp hours (Ah).
So, how to calculate the battery capacity? Let’s assume you want to find out the capacity of your battery, knowing its voltage and the energy stored in it. For example, we have a standard 12V battery and te amount of energy stored in the battery is 24 Wh.
The battery capacity is calculated from this formula:
energy = voltage * battery capacity
battery capacity = energy / voltage = 24 / 12 = 2 Ah
The battery capacity is equal to 2 Ah.
This is the current I used for either charging or discharging your battery. It is linked to the C-rate with the following equation:
current = C-rate * battery capacity
- C-rate – It’s used to describe how fast a battery charges and discharges. For example, a 1C battery needs one hour at 100 A to load 100 Ah. A 2C battery would need just 0.5 hours to load 100 Ah, while a 0.5C battery requires 2 hours.
Runtime to full capacity
It is simply the time t needed to fully charge or discharge the battery when using the discharge current, measured in minutes:
t = 1/C-rate
We have learned in this article how to calculate the drone battery capacity, drone battery energy, discharge current and runtime to full capacity.
Thank you for reading.
If you like to read more you can check other articles on our website:
If you interested in DIY projects with Raspberry PI and Arduino visit Acoptex.com.

Let’s calculate the new amp draw using the basic power equation:
Amps Draw (in A) = 800W/ 240V = 3.33 A
As we can see, the amp draw is no longer 6.67 A; it’s 3.33 A. When we increase voltage, we need fewer amps to get the same electrical power (wattage). Based on this, we can now calculate how long will a 200 Ah battery be able to power an 800 W 240 V air conditioner:
200 Ah Battery Life = 200 Ah / 3.33 A = 60 hours
As we can see, because the amp draw is halved, the battery life is increased. That’s because an 800 W air conditioner on 240V requires fewer amps than an air conditioner on 120V.
Now we know how to calculate the amps from watts. We can use this knowledge to calculate the second vital input into the Battery Life Calculator:
Battery Life Calculator (Insert Battery Capacity And Amp Draw)
When you figured out how big a battery you have (battery capacity in Ah), and how many amps does a device you want to hook on the battery runs on, you can input both numbers in this calculator. As a result, you will get how long will a battery last (in hours):
You can pretty much calculate the battery life for any kind of battery powering any kind of electric device.

A 20 hour test is just as it implies, 20 hours long, not including the time it took you to charge the battery and get it to a controlled temp of 75-80F.
"RC How do I determine my batteries 20 hour discharge rate?"
This part is easy, you divide your batteries 20 hour Ah capacity by 20, eg: 100Ah ÷ 20 = 5A. If you had a 210Ah battery the math is the same; 210 ÷ 20 = 10.5A. If you want to test for Ah capacity, which is the only test that matters for an Ah counter, then this is the formula for determining the constant-current discharge load you will use.
The second thing you will notice is the temperature. Just like the rate of discharge, battery temperature affects your usable capacity. If you do not maintain a battery temp of 75-80F, during testing, you will not arrive at or get the correct 20 hour capacity. When conducting a capacity test, in order to properly program a battery monitor, discharge current and battery temp ideally need to remain constant & stable while the battery is discharged to 10.5V.
If you don’t start with a known & confirmed Ah capacity, your Ah counter may never give you reliable information. It simply can’t unless it is programmed well. At a bare minimum, for cooler climates, a once yearly 20 hour capacity test to 10.5V should be conducted. In warmer climates, defined as average battery temps above 80F, bi-yearly is a much better choice.
How do I conduct an accurate 20 hour capacity test?

We have that; it’s 200 Ah.
- Amp draw. That we don’t have; we have to calculate it.
To calculate amp draw (A) from watts (W), we also need to know the voltage (V). To calculate amps, we use the basic electric power equation:
P (in W) = I (in A) * V (in V)
Basically, electric power P (wattage) is calculated by multiplying electric current I (amps) with voltage V (volts). To calculate amps, you have to express the electric current I (amps) like this:
I (in A) = P (in W) / V (in V)
This basically tells us that we get the amps by dividing watts by volts.
Example: We have an 800 W AC unit that runs on a 120 V electric circuit. What’s the amp draw here? Easy, we just divide 800 W by 120 V and get 800W/120V = 6.67 A.
If you find this confusing a bit, you can use our watts to amps calculator here to help you out with the calculation.
In our example above, we have calculated the amp draw of the 800 W AC. It’s 6.67 A. Now we have both numbers; we have a 200 Ah battery and we know the AC has a 6.67 A draw. How long will a 200 Ah battery last if it has to power this AC? Let’s calculate:
200 Ah Battery Life = 200 Ah / 6.67 A = 30 hours
In short, a 200 Ah battery will be able to power an 800 W 120 V air conditioner for about 30 hours.
Now, it’s important that we feel the effect of different voltages. Let’s say that we have the same 200 Ah battery, the same power input 800 W unit, but it runs on a 240 V electrical circuit instead of a 120 V circuit.
Because the voltage is different, the amp draw – the amps required to run such an AC – will also change.

The more electrode material contained in the cell the greater its capacity. A small cell has less capacity than a larger cell with the same chemistry, although they develop the same open-circuit voltage. Capacity is measured in units such as amp-hour (A·h). The rated capacity of a battery is usually expressed as the product of 20 hours multiplied by the current that a new battery can consistently supply for 20 hours at 68 °F (20 °C), while remaining above a specified terminal voltage per cell. For example, a battery rated at 100 A·h can deliver 5 A over a 20-hour period at room temperature. The fraction of the stored charge that a battery can deliver depends on multiple factors, including battery chemistry, the rate at which the charge is delivered (current), the required terminal voltage, the storage period, ambient temperature and other factors.
The higher the discharge rate, the lower the capacity. The relationship between current, discharge time and capacity for a lead acid battery is approximated (over a typical range of current values) by Peukert's law:
- is the capacity when discharged at a rate of 1 amp.
- is the current drawn from battery (A).
- is the amount of time (in hours) that a battery can sustain.
- is a constant around 1.3.
Batteries that are stored for a long period or that are discharged at a small fraction of the capacity lose capacity due to the presence of generally irreversible side reactions that consume charge carriers without producing current. This phenomenon is known as internal self-discharge. Further, when batteries are recharged, additional side reactions can occur, reducing capacity for subsequent discharges. After enough recharges, in essence all capacity is lost and the battery stops producing power.
Internal energy losses and limitations on the rate that ions pass through the electrolyte cause battery efficiency to vary. Above a minimum threshold, discharging at a low rate delivers more of the battery's capacity than at a higher rate. Installing batteries with varying A·h ratings does not affect device operation (although it may affect the operation interval) rated for a specific voltage unless load limits are exceeded. High-drain loads such as digital cameras can reduce total capacity, as happens with alkaline batteries. For example, a battery rated at 2 A·h for a 10- or 20-hour discharge would not sustain a current of 1 A for a full two hours as its stated capacity implies.

You can quickly get a DMM from the market, turn the DMM selection switch to DC voltage supply, and connect the COMM terminal of DMM with the negative terminal and other terminals of DMM with the positive terminal.
By doing so, DMM will give you the exact output voltage of your battery packs.
You can connect DMM in series to the battery pack to determine the load current, and you can also use an Analog and digital ammeter for it.
You can then use the formula of P=VI to calculate the power capacity of the battery packs.
If you can’t use this method, you should look for the battery manufacturer number on your battery and battery packaging.
You can give this number to your battery manufacturer, and he/she will let you know about its battery capacity.
The American National Standards Institute (ANSI) procedure is as follows: Step 1 discharge new cells at 0.2 C to 1 volt. Step
2 Charge cells at 0.1 C for 16 hours. Step 3 rest cells for 1 hour. Step 4 discharge cells at 0.2 C to 1 volt. Battery capacity is determined by the hours of service to 1-volt times the discharge rate (mA x hours = mAh)
8. What are the protections placed in TLH’s Rechargeable battery packs?
We greatly emphasize user’s safety; hence our technical staff has taken special consideration for the battery protection.
We offer a Battery management system in our battery packs.
Along with BMS, we offer a cell balancing system in our rechargeable battery packs.
On the off chance that your cells aren’t balanced, it could influence your battery execution, subsequently adjusting the circuit is expected to control the battery on the occasion of unevenness.
Using an imbalanced battery will provoke under execution of the battery because the battery will not have the alternative to charge and delivery to its most extraordinary cutoff; like this, it will lessen the constraint of the battery cells.
Balancing the circuit is critical because it charges and deliveries the cells’ aggregate to their most extraordinary worth; this will grow the strength and decrease the chances of deficiency for your battery and device.
In the event that the cells have distinctive voltage levels across the cells, it could bring about ill-advised force appropriation from the phones to your gadget.
A balancing circuit is essential for your battery packs because it enables proper charging and discharging cycles.

Boost the life and performance of your lithium battery by installing the correct charging setup, says Duncan Kent
Before planning a total upgrade to lithium batteries, carry out a consumption audit – an in-depth evaluation of your electrical needs.
Modern appliances consume less power than older models, so you might want to consider using some of your repowering budget in the updating of your kit.
Compressor-driven fridges, for example, can consume less than a third of the budget of thermo-electric cool boxes.
As battery capacity is nearly always quoted in Amp-hours (Ah) it’s often easier to do your calculations in Ah, rather than Watts and Watt-hours.
Firstly, decide on a period (commonly 24h) between charges.
Then, so long as you know what current a device draws, you simply multiply the time it will be in use over that period to get the number of Ah consumed over that period.
Having totalled up your proposed consumption, double it if you plan to use lead-acid type batteries, or for good quality Lithium-ion batteries that will allow an 80% discharge, multiply your consumption figure by 1.25.
That will provide your required battery capacity for your chosen period but I would always add a further 25% for contingencies.
Please note, capacities on deep-cycle batteries are usually quoted in C20 discharge rates, which is a pretty reasonable guide to follow.
Some ‘leisure’ batteries (compromise between a deep-cycle and a start battery) might also quote a CCA (Cold Cranking Amps) figure, which is a good indication that they aren’t proper deep-cycle ‘traction’ type batteries.
They can be used in smaller craft, they’re just not the best for liveaboard cruising yachts.
Charging lithium batteries
AC battery chargers
Lithium-based batteries are usually charged at constant current of between 0.5C-1.0C (C = capacity in Ah) until the current drops to 0.03C, at which point charging must cease so as not to overcharge the cells.
These figures may differ depending on the type of cell and the instructions.
Some recommend you stop charging at 0.1C to reduce stress on the cells and help extend their lifespan.
The State of Charge (SoC) cannot be determined by battery voltage, as this reaches its peak when the battery is only half-charged.

This is a graph of cycle life to delivered capacity for a flooded deep cycle lead acid battery we use in boats quite often. Take a look at how capacity changes with life and cycles. Also remember that in the lab they get 700+ cycles but in the real world most boat batteries are destroyed in well under 200 cycles.
What is Ampere Hour Capacity?
The Ah capacity of deep cycle marine batteries is based on the *BCI (Battery Council International) 20 hour discharge test. For a 100Ah battery this means it should deliver 5A at 77F for 20 hours before the loaded terminal voltage falls to 10.5V. This is your ideal factory rated Ah capacity, but you’ll notice two things.
*WARNING: Many unscrupulous battery manufacturers "calculate" or "extrapolate" the 20 hour rating from other tests using mathematical assumptions, as opposed to actually testing it for a true 20 hour rating. When you buy cheap batteries you often get Ah ratings made up via guess work.
The first thing that stands out is the 5A current. In order to meet the 20 hour capacity test figure, the current is held absolutely stable even as the voltage decays/falls during the test. As a battery discharges, the load it is discharged at will change the usable capacity of the bank, at that load. The only way you can get 20 hours of run time, at 77F, is at the 20 hour discharge rate. Any load greater than this and the battery will not deliver its full rated capacity. On the flip side if we draw the battery at less than the 20 hour rate we can get slightly more Ah capacity out of it.
I prefer to call this the Peukert effect. I hesitate to call it Peukert’s law because it is not a law, like Ohm's Law is, it’s an effect that modifies usable capacity based on rate of discharge.
In order to test the battery at the 20 hour rate, and do so accurately, you ideally need to hold the discharge current steady as the voltage decays to the 10.5V cut off point. This is a tedious and imprecise process for the average DIY. There is test equipment available to conduct a proper 20 hour Ah capacity tests but they begin in the four figure price range, and take a lot of time to complete.

With the example above would need 30 of them to obtain the required voltage, but would still only 7 Ah useful energy to that voltage.
To put it another way, more Ah, we go further and faster. However, more Ah cost more money, and weigh more.
When we read Wh (watt / hour) on battery specifications, we are more or less to what we have been explaining about Ah, but in this case the voltage is also considered. For example, a battery of 360 Wh is only 10 Ah battery to 36 volts (36V 10Ah x = 360Wh).
Maximum current means essentially “what is the maximum download speed of a cell?”. Think of it as a bucket of water. The hub is the cell and water is electricity (the larger the cell, the greater the amount of water), where the water leaves through a hole in the hub. Thus, the larger the hole, the faster will the water.
In terms of battery, if the download (the hole) is not large enough, then the engine may not be able to get enough energy (water) to operate with maximum performance.
The measuring unit is described in terms of maximum amperage that can support cell per unit time. Another way to describe it in terms of “C” or what is the same, the rate at which the battery can be discharged for one hour = 1C. For example, if the battery discharge 10 amps for one hour means you will have a maximum current of 10Ah to 1C.
Problems in construction of batteries :
Most consumer batteries electronics utilize a handful of cells. For example, a battery of a mobile phone of 3.6 volts, may have three NiMH batteries at 1.2 V battery in a plastic box. The electric bikes , usually no more than 30 merged cells. Each cell is connected to another with a small metal connector. Each connector is a potential point of mechanical failure, and a small resistance.
Lead Acid (SLA)
Pros : average energy density, maintenance, proven in millions of electric, cheap bikes.
Cons : heavy batteries, very short life cycles, no fast load option and not easy storage.
Nickel (NiMH and NiCd)
Pros : average energy density, relatively fast loading, average weight.
Cons : suffer from memory, slashing performance at low temperatures, difficult storage effect.

This article will help you to calculate the drone battery capacity, drone battery energy, discharge current and runtime to full capacity.
Drone battery capacity
The drone battery capacity calculated by this formula:
capacity = drone flight time * average amp draw / discharge
The average amp draw calculated:
average amp draw = (total drone weight * power) / voltage
- capacity – It’s the capacity of your battery, expressed in milliamp hours (mAh) or amp hours (Ah). Please note that 1 Ah = 1000 mAh. You can find this capacity value printed on your LiPo battery. So, the higher the capacity, the more energy is stored in the battery.
- discharge – It’s the battery discharge that you allow for during the flight. As LiPo batteries can be damaged if fully discharged, it’s common practice never to discharge them by more than 80%. Basically you need to leave 20 % charge.
- average amp draw – It’s calculated in amperes.
- total drone weight – It’s the total weight of the equipment that goes up in the air, including the battery and measured in kilograms.
- power – It’s the power required to lift one kilogram of equipment, expressed in watts per kilogram. You can normally use 170 W/kg. Some more efficient systems can take less, for example, 120 W/kg; if that’s your case, don’t hesitate to adjust its value.
- voltage – It’s the battery voltage, expressed in volts. You will find this value printed on your battery.
- current – The power / voltage is the definition of an electric current I (in amps) required to lift one kilogram into the air. It comes from the Ohm’s law (power = current * voltage).
Drone battery energy
The power of an electrical device P is equal to voltage V multiplied by current I:
P = V * I
power = voltage * current
The energy E is power P multiplied by time T:
energy = power * time
E = P * T
If you join both formulas:
energy = voltage * current * time
E = V * I * T
The amp hours are a measure of electric charge Q (the battery capacity).

Firstly let me say that this is with a view to using a lead acid battery for backup purposes in case of power outage (mains power, a few lightbulbs but with daily outages lasting a few hours)
So let's provide a data sheet for the battery, deep cycle flooded lead acid type:
For the given battery, the SPRE 12 225, the open-circuit cell voltage is:
- 100% charged 2.122V per cell
- 50% charged 2.017V per cell
- 20% charged 1.943V per cell (11.66V total)
- 10% charged 1.918V per cell (11.51V total)
Meanwhile the capacity of the battery is defined based on discharging (at constant current) in 10, 20, 48, 72, or 100 hours until the cell voltage falls to 1.75V (10.5V total).
According to the manufacturer's data, the total lifetime capacity of the battery (number of cycles * depth of discharge) doesn't appear to be significantly different between 20% and 80% DoD.
So if we want to know how much real capacity the battery has, it seems we can use 12V * C * 80%. The C10 figure is 179Ah, C20 is 204Ah and C100 is 225 Ah. So at C10, 17.9A, that's 12 & 179 * 0.8 = 1718.4W.
However, is it possible that the voltage drop due to the current & internal resistance of the battery is distorting the figures? Or is this insignificant?
The manufacturer do not quote below a C10 figure (17.9A, equivalent to around 170W after inverter & distribution losses). Is this the maximum current draw? Or could you go to, say, C5?
I notice from the manufacturer's datasheet for their renewal energy storage range
that the ratio of, say C10 to C100 isn't completely consistent across battery chemistry, however they do quote C5 numbers for some of the AGM & gel batteries. Is there in fact a possibility to use a higher discharge current for gel/AGM vs lead acid?

|State Of Charge||Sealed Or Flooded Lead Acid battery Voltage||Gel Battery Voltage||AGM Battery Voltage|
Discharge Depth Of Battery
The general rule of thumb: the less you discharge your deep cycle battery before recharging, the longer it will last
An example is here:
Remarkably, a Sonnenschein Solar Bloc 100 AH Gel Battery discharged to a depth of 70 percent, i.e., with just 30 percent or 30 Ah (amp hours) left, would have a lifetime of around 1200 cycles. However, if it only discharges up to 50 percent, the estimated number of cycles will rise to about 1700! That adds over 1.25 years to the life of the battery if a cycle is a day
In most deep-cycle batteries, discharge depth, also known as DOD, should not be more than 50 percent to get the best value for money. So, consider the cut-off discharge depth to be 50 AH if you have a 100 AH battery.
A very critical measurement you can make when selecting the size of a deep cycle battery is the depth of discharge.
Another example is here:
Check the amplifier rating on the adaptor if you want to power a laptop computer. Between the 3 and 5 amp mark, it is likely to be anywhere. This probably translates to around 2-4 amps an hour under regular use as at all times; your laptop will not use the maximum amount. So, on the lower end, centered on:
100 AH battery = 50 AH capacity available/2 amp draw = 25 hours of use.
There are four main types of traditional deep cycle batteries, such as sealed lead acid, flooded lead-acid, gel, and AGM, as stated. See our Deep Cycle Battery Guide to find out more about the difference between them. Find out more about the Tesla Powerwall solar battery.
Recommended Readings (The Baselined)

However, as batteries lose efficiencies over time, a ‘full charge’ can be at 100% of its claimed capacity at the start, but dwindles to 70% after some years. This is why warrantied energy throughput is more useful to determining how long your battery can last. This number shows the amount of electricity to pass through the battery throughout its lifetime.
With this knowledge, you should now be well equipped to buying the right battery for your home. If you want to make the most out of your solar and battery investment, consider getting an energy management system like carbonTRACK, which not only shows the data related to electricity usage, input and output, but can also control appliances in home so that you can maximise your savings from electricity use.

Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.

If you depend on your device to operate straight away after long periods of inactivity, such as an emergency torch, then it's preferable to use a good alkaline single-use battery.
Lithium and alkaline batteries are functionally about the same in nearly all aspects. However, lithium batteries can be used in more powerful devices without having to worry about the battery draining too quickly, as they have a higher capacity, slightly higher initial voltage and a longer shelf life. The downside is lithium batteries are more expensive.
Breaking down the jargon
Milliampere hours (mAh): A measurement of the capacity of a battery. The higher the mAh, the longer the battery will last. If your battery is rechargeable then the mAh rating is how long the battery will last per charge.
Memory effect: Most often associated with NiCad batteries where the battery appears to fail to charge to its full capacity, instead setting itself to show fully charged at the capacity of the battery when placed in the charger.
Claimed capacity mAh: High-drain tasks such as digital photography with frequent use of the flash may benefit from a battery with a higher capacity.
Lithium-ion single use: These last the longest in high-drain devices, like digital cameras, and might be a good option for a backup when travelling. Manufacturers claim they have a shelf life of around 10 years. There are a few online sites offering rechargeable Li-Ion AA batteries. Most of these batteries have a nominal voltage of 3.7V, which will fry your electronic devices if they take normal AA batteries, so avoid them unless you know exactly what devices you have that can cope with a nominal voltage greater than 1.5V.

Sometimes some petty things makes big confusion in our mind, One of those petty thing is calculating our inverter battery Back-up time.
99% of people who own Home inverter would ask this question to their battery dealers at least once in their life time. But most battery shop owners don’t let their customers know the simple formula to calculate the Back-up time of inverter battery. Don’t worry readers, now I will let you know that simple formula!
Formula to Calculate the Back-up Time of Inverter Battery
Back up Time of Inverter Battery = Battery Volt x Battery AH rating / Total watts on Load
If a Person use 1 ceiling Fan + 1 Tube Light + 2 (15watts) CFL simultaneously with 150 AH battery, then the backup time will be calculated as
1 ceiling Fan = 75 watts
1 Tube light = 40 watts
2x 15watts CFL= 30 watts
Total = 145 watts
Back-up time of 150 AH Battery = 12 * 150 / 145
= 12.41 hours (approximately)
This is Not Accurate Why?
This calculation shows only approximate value because there will be some loss of energy when converting 12 v battery power to 220 volts through inverter.
Moreover, we cannot figure out the exact power consumption of ceiling fan, as it has speed adjustment dimmer switch. The power consumption will be low when the fan runs at slow speed.
Note :( Power consumption of old fans with big sized Regulator remains same at all speed points)

Specific gravity measurements in batteries indicate how much sulfate is in the electrolyte, providing information about the SOC, but not capacity or SOH.
- Impedance testing — An impedance test does not measure the capacity of the battery, but it is an indicator of the SOH of the battery.
- Discharge testing — Discharge testing is the only form of test that will determine the actual capacity of the string, but not necessarily the SOH.
IEEE standards (see IEEE Standards At a Glance) recommend that discharge testing be performed at the time of a battery strings installation and then every two to five years after that, depending on the age and capacity of the string. Specially designed test sets are available to make this process as easy and convenient as possible. For complete discharge testing, the battery must be taken out of service for the duration of the test. This can easily last as long as two days in order to allow a full discharge/charge cycle to be completed. Although it offers the most accurate results possible, this test method is clearly costly, time consuming, and often inconvenient. How many users do you know that would be okay without standby power for two full days?
One way of addressing this problem is to carry out limited discharge testing, which involves discharging the batteries by up to 80% without taking them out of service. This yields results almost as accurate as those provided by carrying out a 100% discharge test.
Partial discharge testing is a very useful way of assessing battery condition, but it is not ideal in every application. For one thing, the test is still time consuming. Although the batteries remain in service — should they be called upon to supply power at the point of deepest discharge during the test — they will only have 20% of their full capacity available.
It is also recommended that impedance testing be performed quarterly. Although impedance testing does not directly provide information about battery capacity, it is the only method that reveals the SOH of the battery. Impedance testing can be performed without taking the battery out of service.
As a battery ages, it may corrode, sulfate, dry out, or deteriorate in many other ways, depending on maintenance, chemistry, and usage. All of these effects cause a chemical change in the battery, which, in turn, causes a change in the battery’s internal impedance/resistance.

This precharacterization is derived from data provided by the battery manufacturer, derived empirically, or otherwise determined. This relationship may be represented by data stored in a lookup table or by a mathematical function implemented in hardware, firmware or software.
In one embodiment, the battery capacity tester includes a constant current sink coupled to the terminals of the battery. The constant current sink is constructed and arranged to draw at least two successive, substantially constant currents from the battery. The battery capacity tester also includes a battery characterizer coupled to the constant current sink and battery terminals. The battery characterizer is constructed and arranged to generate a remaining battery capacity based on a predetermined relationship between the internal battery impedance and capacity for the battery. The internal battery impedance is determined based on a battery voltage measured during each current draw. The constant current sink can be implemented as a constant current source coupled to the battery and supplying a constant current to a load having a known resistance for dissipating the currents.
In one embodiment, the battery characterizer includes at least one lookup table containing the precharacterized battery capacity data that can be accessed by the measured internal battery impedance. In another embodiment, a voltage measurement device is coupled to the battery terminals, providing voltage measurements obtained during each constant current draw. In one aspect of this embodiment, the relationship between the internal battery impedance and the remaining battery capacity is represented by ratios of voltages and currents for the known load. In another embodiment, the lookup table is arranged by the difference in applied constant currents, and is accessed using the difference between first and second voltage measurements to obtain the internal battery impedance and associated battery capacity. In another embodiment, the battery characterizer includes a computation element executing a source program to determine the remaining battery capacity as a function of the present internal battery impedance.
In another aspect of the invention, a method for determining a remaining battery capacity is disclosed. The method includes the steps of: (1) precharacterizing a relationship between battery impedance and battery capacity for the battery; (2) determining a present internal battery impedance; and (3) determining the remaining battery capacity using the internal battery impedance based on the precharacterized data.

Yes
Battery Capacity is a measure (typically in Amp-hr) of the charge stored by the battery, and is determined by the mass of active material contained in the battery. The battery capacity represents the maximum amount of energy that can be extracted from the battery under certain conditions. 3600 mAH, Li-Po, Non-removable

When you place batteries in series, the capacity, or mAh of the pack (we will get to this later), stays the same and the voltage is multiplied by the number of cells. For instance, in the above example of 3s1p, the pack would have a resting voltage of 11.1V (3 x 3.7V). Using this information, a 2s1p pack would have a resting voltage of 7.4V (2 x 3.7).
The next letter in the pack configuration descriptor is p. The p stands for parallel. When placed in parallel, the battery’s voltage is not affected, but the capacity (mAh) is multiplied by the number that comes before the p. For example, if you had a battery that was 1000mAh and had a pack description of 1s3p, your pack would have 3 x 1000mAh cells.
Using this information, if you had a pack that was 1000mAh and the pack description of 3s2p, this would mean that your battery pack consists of two sets of 500mAh cells connected in parallel to make the 1000mAh capacity. In the above example, I referred to the capacity of a battery as mAh. mAh stands for milliamp hour. 1000mAh is equal to one amp hour. For example, a battery that is rated at 3000mAh can be discharged at a rate of 3 amps (or 3000mAh) for one hour before being completely drained. By this logic, if you drained the same 3000mAh at 6 amps, the pack would be completely drained in one half hour.
Rating the battery
The next term that is very important to understand when it comes to batteries is the C rating. Batteries carry c ratings from 1C all the way up to 45C these days. The C rating is basically how fast the energy of the battery can be released from the battery. If a 3000mAh battery has a 1C rating it can be discharged safely at 3 amps. If you have a similar 3000mAh battery with a C rating of 10C that battery can safely be discharged at 30 amps. The same battery at 20C can be safely discharged at 60 amps, etc.

- Configuration: How many cells the battery has. (1S, 2S, 3S)
- Capacity : How much electricity the battery holds. (500 mAh, 1000 mAh, 2200 mAh)
- Constant discharge: How fast the electricity can flow from the battery. (15C, 25C, 35-45C)
- Burst rate: A peak value that the battery can discharge for a short period of time. (37C ,15sec)
- Pack size: three dimensions, HxWxL
- Weight: in these modern times, always expressed in grams.
- Charge Rate: how high of a current at which the battery can be charged (1C, 5C)
Lots of details here.
Voltage: A single lipo cell will have a voltage range of 3.0V - 4.2V. The "nominal" voltage (how it's typically referred to) is 3.7V. If the cell goes below 3.0V, it won't be able to be recharged. Most people recommend not letting a cell go below 3.2 volts so that you'll have a bit of safety margin.
So, a 3S battery will have 3 cells, a nominal voltage of 11.1V, and a voltage range of 9V - 12.6V (the nominal values multiplied by 3.
Your discharge rate requirements will be defined by your motor and ESC combination. Models with high instantaneous power demands (helis, stunt 3D flying) will have higher discharge requirements. Models with low instantaneous power demands (gliders, trainers) will have lower requirements. Higher discharge rates usually mean the batteries will be heavier and more expensive.
- Configuration : 2S 7.4v
- Capacity : 2150mAh
- Constant discharge: 25C
- Burst rate: 37C (15sec)
- Pack size: 113x33x16mm
- Weight : 129g
- Charge rate not specified, so we assume 1C

In a battery, a chemical reaction occurs and then electrons travel through a wire from one terminal to the other, and the result is Direct Current (DC) electricity. Batteries are particularly useful for standalone systems as they are fairly cheap and power can be stored and used when needed. If you wish to store electricity that you have generated in the battery bank then deep cycle batteries are designed to deliver less current for a longer period of time. Once flat they are designed to be recharged.
Car batteries can be used but they are not suitable as they are not designed to be fully discharged. The deep cycle batteries are designed to be recharged once flat and will last longer.
The amount of energy that a battery can supply is specified in ampere hours (Ah). So, a 12-volt battery that is specified as 100Ah can theoretically deliver 1 amp for 100 hours or 100 amps for 1 hour.
Multiplying the volts and amps, gives you the power (watts) the battery will produce.
So for our 12 volt battery it is possible to have:
- 12 volts X 1 amp = 12 watts for 100 hours
- 12 volts X 100 amp = 1200 watts for 1 hour
Back in the real world, these numbers don’t quite add up as you can’t expect to get more than 80% capacity from your battery, i.e. 80 Ah.
The smaller deep cycle batteries are not designed to deliver masses of current so you shouldn’t really drain more than about 10 -15 amps (that’s a device of about 120 – 180 watts). So if a pump needs 60 watts to function we divide 60 watts by 12 volts, which gives 5 amps.
If you use the pump for 2 hours a day, a fully charged battery therefore lasts about 8 days.
How to work out Watts, Amps and Volts
Common sense states that a larger Solar Panel will collect more energy than a smaller solar panel, but what size is correct for your needs?
Most power consumption of appliances is given in Watts. It is a relatively simple calculation to work out power your energy use, just multiply the power consumption by the hours of use.

However, that requires a deep discharge which lead-acid batteries don't like. It also causes you to lose radio settings. The measurement would take many hours, something for which garages don't have time.
If you know the current draw from your headlights, you could leave the car with the headlights on and see for how many hours they are still on. For example, if the headlights are 120W = 10A @ 12V, it means that a 50 Ah battery should be able to keep the headlights on for 5 hours. This will however, as I said, lose your radio settings.

As a result, to ensure reliable defibrillator operations, it is critical that the condition of the battery pack be determined prior to operation. The user may then determine whether the installed or a replacement battery should be used.
Currently, three procedures or tests are commonly utilized to determine the present capacity of a battery, referred to herein as "remaining battery capacity." One conventional battery capacity test measures the time to completely discharge a fully charged battery into a known load. One drawback is that this technique requires a known load to be provided over a very long period of time. Inclusion of such a long load discharge cycle significantly increases the cost and complexity of the procedure. Another deficiency is that this test often requires hours to perform since the battery must be fully charged, and then fully discharged. Furthermore, since the battery must be completely discharged under well-known and controlled conditions, the battery powered device is unavailable for use during this test. In addition, for the battery to be used, it must be fully recharged upon completion of the test, further extending the unavailability of the battery. An additional problem is that this test decreases battery life for certain types of batteries such as NiCd or SLA batteries, reducing the number of remaining available charge cycles. Thus, although relatively accurate, this test is time consuming, inconvenient, and adversely affects the battery life and availability.
Another conventional battery capacity test, commonly referred to as an open circuit voltage test, measures the battery voltage without an attached load. This test is utilized only for certain types of batteries, such as SLA batteries, which are characterized by a predictable decrease in terminal voltage as the battery is used. The remaining battery capacity is estimated based on this decrease in voltage. However, many other battery types such as lithium batteries, silver batteries, and mercury batteries do not exhibit such a continual and predicable decrease in voltage during use. As a result, this test is not suitable for such batteries. In addition, this test is also temperature dependent. The ambient temperature will effect the battery voltage and thus the estimation of battery capacity. Also, if the battery is partially depleted, this test will be less accurate because the relationship between voltage an capacity will have changed. Thus, although relatively fast and roughly accurate, this test can only be utilized to test a minority of battery types.

An AA alkaline battery's voltage starts at 1.5 and drops to 0.8V cutoff.
This makes alkaline a poor choice for powering an LED. You want a flatter discharge curve. Li-ion is a much better choice. You could easily power these LEDs with a single 18650 battery.
The lifespan is determined by the discharge rate. At 25mA expect 3000 mAH. At 100 mA expect 2500 mAH. See ENERGIZER E91 Specifications The mid point would be 2750 mAH.
Three AA alkaline in series will have a discharge curve from 4.5v to 2.6v. A better value would be 11Ω which would give you 75 mA at the 3.6V mid point between new 4.5V and discharged to 2.77V.
Each one of these LEDs must/should have a current limiting resistor. You measured 76 mA which is only valid for whatever the battery voltage was at that instant. The voltage is continually decreasing as well as current.
First you must specify the current required for the desired brightness. The use an online calculator to get the value of the optimum resistor. I like the Hobby Hour LED Series Resistor Calculator
At 75mA each LED uses 12.5 mA.
A 3.6V 18650 Li-ion will discharge to 3.2V, a much flatter curve. At 4.5V an LED with a Vf of 2.77 would use a 140Ω resistor for 12.5mA. For 12.5mA at the minimum 2.77V the optimum resistor would be 10Ω. The resistor to use would be calculated with the mid point voltage of 3.6V which is 66Ω. But the range of brightness would be noticeable. This will give you an average of 45 mW per LED or 270 mw for all 6 LEDs. With a battery capacity of ≈2750 mAH would yield a lifespan of 36.66 hours with an average 76% efficiency.
If you need a very consistent brightness then a constant current regulator would be required. something like an On-Semi NSI45060JD would work okay. For higher efficiency a switching step down regulator may do better.

For certain situations, such as an off-shore passage or open ocean racing discharging to 70-80% DOD is acceptable provided the batteries receive a proper charger as soon as you get to the destination. Regularly discharging below 50% SOC on a regular basis in a PSOC environment drastically shortens battery life when compared to 50%.
Firefly & some GEL batteries would be an exception for regularly discharging below 50% SOC.
How do I conduct an approximate 20 hour capacity test?
#1 Allow battery to attain a steady 75-80F temperature
#2 Fully charge battery and equalize if it's capable
#3 Let the battery rest for 24 hours
#4 Apply a DC load for 2 hours that = Ah Capacity ÷ 20 (small light bulbs and/or resistors can work)
#5 Allow the battery to rest for at least 10 hours at 75-80F (24 hours is significantly more accurate)
#6 Check specific gravity or resting open circuit voltage and compare to manufacturers SOC tables
#7 Use basic math to determine the approximate Ah capacity. For example, a 100Ah rated battery has been discharged at 5A for 2 hours. This means so you removed 10Ah's of capacity. If the battery was in perfect health specific gravity readings or open circuit voltage readings should show the battery at 90% SOC. *If SG and OCV only show the battery at 60% SOC then the battery has lost approx 30% of it's Ah capacity.
This is an approximation only and NOT an accurate Ah capacity test. Variances can be anywhere from 10-18% off an actual 20 hour capacity test depending upon your particular battery.

In such embodiments, a microprocessor or general-purpose computer (not shown) is utilized to execute a source code program stored either in RAM or ROM, performing the computation or accessing the look-up table to determine battery capacity. The source program may be implemented any language suitable for creating a source code file executable by the microprocessor. For instance, C, C++, Basic, Fortran, Assembly, and Pascal programming languages may be used.
In one embodiment, the source code program would have as an input the first and second voltage measurements corresponding to the first and second current levels, respectively. Thus, the source code program would provide the internal battery impedance as a direct calculation using the formula (1) shown above. Using the mathematical relationship between the internal battery impedance and remaining battery capacity developed as described above, the internal battery impedance is used to determine the remaining battery capacity.
A flowchart illustrates one embodiment of a method 600 for determining the internal battery impedance and remaining battery capacity for a battery under test is provided in FIG. 6. In step 602, the internal battery impedance is determined. In step 604, the remaining battery capacity is determined using the internal battery impedance and the precharacterized data.
FIGS. 7A and 7B are a flowchart of one embodiment of a process for determining the internal battery impedance and remaining battery capacity for a battery under test. In steps 702 through 706 data relating the internal battery impedance to the remaining battery capacity is pre-characterized. For each different battery chemistry being considered, that battery's particular data is appropriately stored. In step 708 a first current is selected and the battery discharges the current to a known load, during which time the battery voltage is measured step 710. In step 712 a second current is selected and the battery discharges the current to the known load, during which time the battery voltage is measured step 714. The internal battery impedance is determined based upon the voltages measured and/or the currents used, step 716. The remaining battery capacity is then determined in step 718 and is output in step 720.
In one embodiment of the present invention, step 704 may be implemented in a look-up table storing the precharacterized data in a memory device that is accessible to the controller. The data may be stored according to a variety of methods including a linked list, table, data structure, or array.

The amperage is not additive in series.
In order to build current, we connect batteries in parallel (positive to positive, and negative to negative). If we want 200 amps per hour and we're using a 50-amp/hour battery, we need four rows of these batteries, connected in parallel. Voltage is not additive in parallel.
To determine how many batteries you would need, first calculate your average hourly watt needs, and divide by 120 volts AC to find amperage per hour.
The minimum battery bank for off-grid use is typically designed for fourteen hours – the time from sundown to sunup. If you're on the utility grid, you need enough reserve to last through a power failure – usually four hours at most.
Your system can be 12-, 24-, or 48-volts DC. Of these, 48-volt is most common because of its greater efficiency. The type of system determines the multiple you will now find your DC amp hour requirement. This multiple is 10 for a 12-volt system, 5 for 24-volt, and 2.5 for 48.
So, multiply your amps per hour from the last paragraph (let's assume 10 amps/hour) by the multiple for your system (assume 48-volt) to get your DC amp/hours (25).
Select the deep-cycle battery you will be using and determine the reserve amps for that battery. Multiply your amps per hour (from above) by 14 hours. This gives your battery reserve amp as required.
Divide that by battery manufacturer reserve amps, and you will know how many rows of batteries in parallel you need. The number of batteries in series in each row is determined by the battery voltage. Batteries are most commonly 6 or 12 volts.
Now divide the system voltage (12, 24, or 48) by the voltage of your batteries (6 or 12). This gives you the number of batteries per row.
Finally, multiply the number of batteries per row by the number of rows to find the total number of batteries.
Let's say we're building an off-grid system. Our monthly energy requirement is 576.45 kWh.

It is recommended to fly using only 80% of the capacity of LiPo batteries to maximize their longevity so using the 9.11A average from the example above, the full throttle current draw (you will need to measure this) is 16A, input 2200mAh and 16A into the app and it'll calculate that you should be able to fly (at FULL throttle) for 6 minutes 36 seconds until the battery is 80% depleted or for 8 minutes 15 seconds (also at FULL throttle) until it is 100% depleted. (Img #2)
A "Realistic" flight time for a plane is also calculated which works out to be 11 minutes and 47 seconds using 80% capacity and 70% average throttle, very close to the actual flight time in the first example.
For helicopters and multicopters the flight time is very dependant on what style of flight, but you can use the calculator to calculate the expected flight time in a hover.
Future plans: Add wing loading, cubic wing loading calculator, + suggestions?
Disclaimer: The formulas used in these calculations come from various internet sources, with some variations added from my own experience. Your results may vary! While a lot of effort was put into ensuring accuracy, this app is not intended to be professionally accurate.
Comments & suggestions very welcome.
|Category||Thread||Thread Starter||Forum||Replies||Last Post|
|New Product||Walkera RC Magic Cube MTC-01 Devo Transmitter Module for 2801pro and Android||zadaw||Micro Helis||114||Jun 30, 2014 07:46 PM|
|Discussion||RC Flight Log Apps for the IPhone or Android||Sticky Mickey||Australia||8||Sep 16, 2013 10:07 AM|
|New Product||Android Phone App - RCEcalc - Electric Flight Calculator||pardus||Electric Plane Talk||0||Jan 14, 2011 02:43 AM|
|Discussion||Android Phone Center of Gravity Calculator for planes||pardus||Product Announcements||4||Oct 25, 2010 03:24 AM|
|Discussion||Android app for calculating Roll Out and Final Drvie Ratios||jimbo-69||Car Talk||5||Oct 19, 2010 03:18 PM|

Figure (1), illustrate the capacity drop of 11 Li-polymer batteries that have been cycled at a codex laboratory. The 1,500m Ah pouch cells for mobile phones were first charged at a current of 1,500mA (1C) to 4.20V/cell, and then allowed to saturate to 0.05C (75mA) as part of the full charge saturation. The batteries were then discharged at 1,500mA to 3.0V/cell, and the cycle was repeated. The normal limit loss of Li-ion batteries was uniform over conveyed 250 cycles, and the batteries function as expected.
//need to put figure number//
Figure (1): capacity drop as part of cycling. Eleven new Li-ion were tested on a codex C7400 battery analyser. All packs started at a capacity of 88_94% and decreased to 73_84% after 250 full discharge cycle.
Courtesy of Codex // maybe change title //
Although a battery should deliver 100% capacity during the first year of service, it is common to see lower then specified capacities, and shelf life may contribute to this loss. In addition, manufacturers tend to overrate their batteries, knowing that very few users will do spot-checks and complain if low. Not having to match single cells in mobile phones and tablets, as is required in multi-cell packs, opens the floodgates for much broader performance acceptance. Cells with lower capacities may slip through cranks without the consumer knowing.
Very identical to a mechanical device that defect quicker with heavy use, the battery’s cycle count depends on the depth of discharge (DOD). The smaller the discharge (low DOD), the longer the battery will last. If at all possible, avoid full discharge and charge the battery more often between uses. Partial discharge on Li-ion is accepted. This battery does not require a complete discharge cycles as there is no memory effect. The exception may be a periodic calibration of fuel gauge on a smart battery or intelligent devices.
Table (2) compare the number of discharge/charge cycles Li-ion deliver at various Depth of discharge (DOD) levels before the battery capacity drops to 70%. All other variables such as charge voltage, temperature and load currents are set to voltage default setting. (DOD) constitute a full charge followed by a discharge to the indicated percentage levels in table.

The number of bits of the analog-to-digital converter will depend on the particular application. In one embodiment, a 12 bit converter is utilized.
In one embodiment where the relationship between the internal battery impedance and capacity of battery 102 is complex and not easily represented by a mathematical function, the precharacterized relationship is preferably stored as data points in a memory. In one particular embodiment, the data is stored in one or more look-up tables. Alternatively, where the relationship may be easily represented by a mathematical function, an algorithm implementing the function may be utilized rather than one or more look-up tables. FIG. 5 illustrates one embodiment of a look-up table 500 containing the precharacterized data relating the internal battery impedance to the remaining battery capacity. Look-up table 500 can be stored in a memory device or a region accessible to battery capacitor calculator 404. In one embodiment, look-up table 500 includes multiple look-up tables, each corresponding to a particular battery chemistry. In the illustrative embodiment shown in FIG. 5, there are three lookup tables 504, 512 and 514 representing precharacterized data for SLA; Lithium, and NiCd batteries, respectively.
In an alternative embodiment, the precharacterized data may also be arranged according to the difference in successively applied currents, Δi. In such an embodiment, individual or linked tables, each identified by a particular Δi, are included in table 500. This current can be different for some batteries produced by different manufacturers having different construction methods or having different battery chemistries. Different battery chemistry types have different load and current capabilities. In addition, each look-up table can also be identified by a temperature or temperature range for which it contains data. Thus, a look-up table for a particular battery can be identified both by the temperature or temperature range and by its chemistry type. In the illustrative embodiment, each lookup table contains 3 columns of data. The first column 506, represents the difference between the first and second voltage measurements. The second column 508, represents the value of the internal battery impedance as determined by equation (1). The third column 510, contains the precharacterized data of the remaining battery capacity associated with the internal battery impedance. The associated battery impedance is the associated Δi divided by the Δv for the particular table or list.

- Lithium-ion batteries are cheaper to produce, and consequently also cheaper for consumers to purchase. They can potentially store 3 to 4 times more charge compared to other batteries of similar size. They also last longer over a period of time and can be recharged more times. There can however be problems storing the batteries, they do not like high temperatures; which could be a consideration if you are buying a device to take with you on your next trip to Mount Vesuvius. Lithium-ion batteries are cylindrical and resemble batteries in your TV remote. There can be one or multiple of these used in a power bank.
Both these batteries have internal capacity, measured in mAh, and nominal voltage measured in V.
How long will a power bank last?
Figuring out how many charges a power bank will give you is not as simple as you might think. First, you need to understand all the various indications.
What is mAh?
This tells you the number of hours the power bank can sustain the current. Normal smartphone adapters have a 1000mA output. Thus, an hour of charging will fill your phone with 1000mA of power. But you are mistaken to think that a 5,000 mAh power bank can charge your phone 5 times.
The indication of mAh is merely the internal capacity of the battery. It is not what the power bank is able to deliver on output.
What is volt?
The voltage of a power bank, or the nominal power, indicates the battery strength. Most power banks are 3.7 volts but the output voltage can be higher. All power banks have an output of 5V or higher.
It is important to note that when more than 1 Lithium-ion battery is used, the voltage does not increase. The mAh capacity increases as the batteries are connected in parallel and the capacity is added together. The voltage however stays consistent and does not accumulate.
Calculating the actual capacity of a power bank
It is time to do some math.
Firstly, the nominal voltage (for example 3.7V) needs to be converted to the output voltage of usually 5V.
Next, one must also factor in that the power bank will not deliver 100% of its charge available. The circuit will use energy too and over time the capacity depletes. The quality of components in the circuit will determine the rate of energy loss, i.e.

There are several characteristics of every battery that distinguishes them from each other such as battery capacity, energy density, voltage stability, self-discharging, size, chemistry, and brand etc. Lithium-ion batteries are available in different sizes one of which is AA size, which is a standard cell size. In this article, we’re gonna be talking about the battery capacity of AA size Lithium ion batteries and how long they last.
Do You Know How Many mAh a Lithium AA Battery Is?
Battery capacity is defined as a measure of the charge a battery stores and is determined by the chemistry used to manufacture the battery. In other words, the battery capacity means the maximum amount of energy that can be taken out from the battery under certain specified conditions. However, the real energy storage capacity of the battery may differ significantly from the "nominal" rated capacity, as the battery capacity depends strongly on the past usage history, storage temperature, age, and the discharging or charging regimes of the battery.
Battery capacity is expressed in mAh (milliamps × hours). For instance, if a battery has the capacity of 250 mAH and provides 2 milliamps average current to a load, the battery will last 125 hours, in theory. However in reality, the actual battery life depends on the way the battery is discharged. Discharging a battery at the manufacturer-specified rate normally helps the battery provide close to its nominal capacity.
After doing some research, we’ve found that AA size lithium batteries of different brands have different capacities. AA Energizer Ultimate Lithium batteries have the highest capacity of all that is 3000 mAh. They proved unsurpassed in performance against a number of real-world usage situations such as remote controls, digital cameras and portable lights, after strict testing against competitors from around the world, and even they now hold a Guinness world record title for the longest-lasting battery. They do not only provide record-breaking performance, but they are lightweight, a leak resistant design and have a 20-year shelf life.
On the other hand, we’ve AA size USB rechargeable Lithium-ion batteries that have the 1200 mAh capacity. They are commercially made for remote controls, toys, fans, flashlights, wireless keyboard and mouse, arm clock, cameras etc. They have built-in USB port that can be plug into any USB port to get them charged.
How Much Longer Do Lithium AA Battery Last?

Ahm. Best bet is to go to Battery University, http://www.batteryuniversity.com
for more than you wanted to know about batteries.
In your case " Lithium-ion is a low maintenance battery, an advantage that most other chemistries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life. In addition, the self-discharge is less than half compared to nickel-cadmium,
Despite its overall advantages, lithium-ion has its drawbacks.
Aging is a concern with most lithium-ion batteries and many manufacturers remain silent about this issue. Some capacity deterioration is noticeable after one year, whether the battery is in use or not. The battery frequently fails after two or three years. "
Don't worry about cycles or memory. Read the site, however, it is outstanding.

Because you must have a battery that is powerful enough to deliver those amps without overheating, shutting down, blowing a fuse, etc.
Generally, a 10ah battery will work well with a 20 Amp controller or less. If you know some of the specs but not all of them, you can do the math but once again be sure you have the correct and honest data to begin with. Sometimes some controllers have " Watt ratings" while others will show "Max Amps" and this can lead to confusion.. When a controller is rated for Watts, you need to know if this is "Maximum watts" or "Continuous watts" with a higher peak. Your battery needs to safely handle the "Peak" or "Max" when needed.
Quality: a battery pack is only as good as it's weakest cell, and as durable as the thing you put it in! Back in the old days (oh god.. Did I just write that ?.. urgh) getting a lasting pack was pure random luck and a rare thing at that. A pack that lasted a few seasons or survived a 6 month vacation on a bench without self-discharging to death was a rare thing. Battery packs and cells have improved greatly and today in 2017 we finally have reached a point in evolution that reliability and quality packs are readily available, it's the finer details that matter most, like getting one from a reputable vendor who will back a warranty and who sells enough of them quickly to keep recently built packs in stock.
BMS and Chargers, to protect and charge your pack. Lithium batteries are light and durable but they must be used within their specified limits. In order to insure a long life, battery packs should contain a BMS, aka: Battery Monitoring System. It stands between the actual battery and the power wires, monitors all the voltages of cells within and also typically watches how many Amps are flowing. If any limits are reached the BMS should intervene by cutting off the power safely. In a perfect world, the BMS will sit there and do nothing but if you do ride until you use up all the energy available, it will shut you down and prevent any damage to the battery cells.

Much of what is mistaken for the 'memory effect' is voltage depression,
which is caused by long, continuous overcharging, which causes crystals to grow
inside the cell. Fortunately both the 'memory effect' and voltage depression
can be overcome by subjecting the battery to one or more deep charge/discharge
Another term you will hear is 'cell
reversal'. This can occur when a battery of cells is discharged below its safe
1.0 volt per cell. During this discharge, differences between individual cells
can lead to one cell becoming depleted before the rest. When this happens, the
current generated from the remaining active cells will 'charge' the weakest
cell, but in reverse polarity. This can lead to the release of gas and
permanent damage to the battery pack.
NiCads can short circuit due to the build up
of crystals inside the battery. The use of a fully-charged electrolytic
capacitor placed across the cell can effect a temporary cure. Over-discharging
of batteries invites short circuiting. Batteries should be stored charged. A
lifespan of 200 to 800 charges is typical for NiCad batteries.
Nickel metal hydride (NiMH)
Like NiCads, nickel-metal hydride cells
provide 1.2 volts per cell. Battery makers claim that NiMH cells do not suffer
from the 'memory effect' and can be recharged up to 1000 times.
NiMH cells are not quite as suitable as NiCads for
extreme current loads, but do offer a greater capacity in the same cell size. A
typical AA NiCad may have a 750 mAh, but a NiMH may provide 2400 mAh - three times the capacity.
If your style of portable operating involves going out for 3 or 4 hours and running around 5 watts output, NiMH cells are an excellent choice and are lighter than sealed lead acid.
Where to get them? 7.2 volt battery packs are often used for models. Two in series gives 14.4 volts, but you'll get over 16 volts immediately after charging. That's above what many commercial rigs are rated so use at your own risk.

It’s important to have a basic idea of how long your marine battery will last on a single charge, especially when it’s powering your trolling motor. If your battery dies unexpectedly, you could find yourself stranded out on the water.
But is there any way of knowing how long your battery may last?
How long will a marine battery run a trolling motor on a single charge?
What factors can affect your battery’s run time?
And is there any way to make a battery last longer between charges?
In this article, we’ll answer all of these questions and more.
Table of Contents
- How Long Does a Marine Battery Last on a Trolling Motor?
- How Can I Calculate the Battery Run Time on a Trolling Motor?
- Can I Make the Battery Last Longer?
How Long Does a Marine Battery Last on a Trolling Motor?
The question seems simple enough: how long can you expect your battery to last? How many hours of power will your trolling motor have per battery charge?
Unfortunately, the simplest answer to this question is, it depends. Every battery and trolling motor is slightly different, and there are many different variables that may influence how long your battery is going to last.
Because of these variables, the same battery may run your trolling motor for a given amount of time on one boating trip and for a completely different amount of time on another trip.
Let’s take a closer look at these variables.
What Factors Impact the Run Time of a Marine Battery on a Trolling Motor?
One of the most important numbers when figuring battery run time is the amp hours, or Ah. This number should be given on all marine batteries. It denotes the amount of amperage the battery could supply over a given time period.
For example, let’s consider a marine battery with a 100Ah rating. Fully charged, and under perfect conditions, this battery could supply your trolling motor 100 amps of power for one hour, 50 amps for 2 hours, 25 amps for 4 hours, 10 amps for 10 hours, etc.
As you can see from the example above, how long the battery lasts depends on how many amps your trolling motor is consistently drawing from the battery. The lower the amp draw, the longer the battery will last.
Marine batteries come with different amp hour ratings. Some have 50Ah or 75Ah ratings, many have 100Ah or 120Ah ratings, and some even have 200Ah ratings.

Ok, time to crunch some numbers and get down to the nitty gritty of it. All batteries and battery packs will have fine print, listing various things of high importance, put on the bifocals and squint, expect to find things like :
Volts: Used to describe how fast electrons move, more voltage = more speed !
Amps: How wide the road is, more lanes, more cars can pass at the same time side by side...
Watts: The combination of Volts and Amps ( Volts X Amps = Watts )
Amp Hours: Should always be listed, typically 10 to 20 Amp Hours ( abbreviated " Ah " ) a measure of how many fixed number of Amps a battery can sustain for 1 hour.. ( C rate ). Or, double the amps for half the time.. Or half the amps for two hours.. etc.
Watt Hours: This is a far more accurate way to know how much usable energy is in a given battery pack ( abbreviated Wh ) when available, this is the number to look for! Also, you can translate it into how many watts, continuous, for 1 hour! A 500wh battery can deliver 500 watts for 1 hour or 1000w for 30 minutes.... or 250w for 2 hours .. etc.. Most ebikes do not use power at an exact level, continuously, so this does not directly translate into ride time, but you can quickly see how a larger battery with more energy (capacity) can deliver lower power levels for longer periods of time, and go further on a charge.
|Load||Run Time (hours)|
|500 wh||250w||2 hours|
|500 wh||500w||1 hour|
|500 wh||1000w||30 minutes|
A word of caution, some vendors are prone to bending the truth and "over-promise" when it comes to range expectations. Be sure to do some research before you buy, ask the right questions and by from a vendor that provides range estimates in relation to your weight, bike, intended use and intended input.
Ah vs Wh: This can get confusing, but it is very important to understand the difference. Amp Hours (Ah) means nothing unless you factor in the voltage. Watt Hours (Wh) is far more important because it factors in the Voltage and the Amp Hours together and determines how far you might go on a full charge.

For rechargeables, it can mean either the length of time a device can run on a fully charged battery or the number of charge/discharge cycles possible before the cells fail to operate satisfactorily. For a non-rechargeable these two lives are equal since the cells last for only one cycle by definition. (The term shelf life is used to describe how long a battery will retain its performance between manufacture and use.) Available capacity of all batteries drops with decreasing temperature. In contrast to most of today's batteries, the Zamboni pile, invented in 1812, offers a very long service life without refurbishment or recharge, although it supplies current only in the nanoamp range. The Oxford Electric Bell has been ringing almost continuously since 1840 on its original pair of batteries, thought to be Zamboni piles.
Disposable batteries typically lose 8 to 20 percent of their original charge per year when stored at room temperature (20–30 °C). This is known as the "self-discharge" rate, and is due to non-current-producing "side" chemical reactions that occur within the cell even when no load is applied. The rate of side reactions is reduced for batteries are stored at lower temperatures, although some can be damaged by freezing.
Old rechargeable batteries self-discharge more rapidly than disposable alkaline batteries, especially nickel-based batteries; a freshly charged nickel cadmium (NiCd) battery loses 10% of its charge in the first 24 hours, and thereafter discharges at a rate of about 10% a month. However, newer low self-discharge nickel metal hydride (NiMH) batteries and modern lithium designs display a lower self-discharge rate (but still higher than for primary batteries).
Internal parts may corrode and fail, or the active materials may be slowly converted to inactive forms.
Battery: Physical component changes
The active material on the battery plates changes chemical composition on each charge and discharge cycle; active material may be lost due to physical changes of volume, further limiting the number of times the battery can be recharged. Most nickel-based batteries are partially discharged when purchased, and must be charged before first use. Newer NiMH batteries are ready to be used when purchased, and have only 15% discharge in a year.
Some deterioration occurs on each charge–discharge cycle. Degradation usually occurs because electrolyte migrates away from the electrodes or because active material detaches from the electrodes.

(Last Updated On: March 3, 2021)
What is a Battery?
A battery is a device for electrical storage. Just as a water tank stores water for potential use, storms do not produce electricity; they keep it. Electrical energy is stored or released as the chemicals in the battery change. This process can be replicated several times in rechargeable batteries. Batteries are not 100 percent efficient – when charging and discharging, some energy is lost as heat and chemical reactions. If a battery uses 1000 watts, it can take 1050 or 1250 watts or more to recharge it completely.
Voltage & State Of Charge Of Deep Cycle Battery
If you are the owner of a mobile or off-grid solar energy device, calculating how much charge you have left in your deep cycle battery bank is one of the most obsessive pastimes. This is often referred to as the’ state of charge.’ Most individuals see the battery voltage as a measure of this. While not entirely accurate, if your solar regulator or charge controller does not have a voltage reading, the best way to assess this is with a multimeter. The state of charge varies slightly between types of sealed lead acid, flooded, gel, and AGM deep cycle batteries and between brands. The weather can also play a part.
Battery voltage status of the charging table charging table
For each type of battery, the table below shows the voltage and estimated state of charge.
Note: The statistics are based on readings from open circuits. That is when there is no load on the deep cycle battery, and it hasn’t been under load for a few hours. In a battery-powered device that is in continuous use, this scenario can not occur very often. So, the best time to read is early in the morning until your panels are struck by the sun, at night when the sun is setting, or when it’s very overcast. If you take a reading when the battery is getting a charge, something up to 14.5 volts could be read.
Take the reading while the panels are not exposed to the light, as power is presumably being drawn at the moment. You might conclude that it is a conservative approximation regardless of the voltage reading. Once all the load is removed from a battery, the voltage will dramatically bounce back up.

Now, Severson and her colleagues report in the journal Nature Energy that machine learning can help to predict computer battery life by creating computer models. The published algorithms use data from early-stage charge and discharge cycles.
Normally, a figure of merit describes the health of a battery. It quantifies the ability of the battery to store energy relative to its original state. The health status is 100% when the battery is new and decreases with time. This is similar to the state of charge of a battery. Estimating the state of charge of a battery is, in turn, important to ensure safe and correct use. However, there is no consensus in the industry and science as to what exactly a battery’s health status is or how it should be determined.
The state of health of a battery reflects two signs of aging: progressive capacity decline and impedance increase (another measure of electrical resistance). Estimates of the state of charge of a battery must therefore take into account both the drop in capacity and the increase in impedance.
Lithium ion batteries, however, are complex systems in which both capacity fade and impedance increase are caused by multiple interacting processes. Most of these processes cannot be studied independently since they often occur in simultaneously. The state of health can therefore not be determined from a single direct measurement. Conventional health assessment methods include examining the interactions between the electrodes of a battery. Since such methods often intervene directly in the system “battery”, they make the battery useless, which is hardly desired.
A battery’s health status can also be determined in less invasive ways, for example using adaptive models and experimental techniques. Adaptive models learn from recorded battery performance data and adjust themselves. They are useful if system-specific battery information are not available. Such models are suitable for the diagnosis of aging processes. The main problem, however, is that they must be trained with experimental data before they can be used to determine the current capacity of a battery.
Severson and her colleagues have created a comprehensive data set that includes the performance data of 124 commercial lithium-ion batteries during their charge and discharge cycles. The authors used a variety of rapid charging conditions with identical discharge conditions. This method caused a change of the battery lives. The data covered a wide range of 150 to 2,300 cycles.
The researchers then used machine learning algorithms to analyze the data, creating models that can reliably predict battery life.

For every 0.10V drop under 4.20V/cell doubles the cycle and keeps less capacity. The more the voltage above 4.20V/cell would the less the longevity.
Guideline: for every 70mV drop in charge voltage reduces the usable capacity by approximately 10%.
|[150 – 250]
300 – 500
600 – 1,000
1,200 – 2,000
2,400 – 4,000
Table (4) represents discharge cycles and capacity as function of charge voltage limit. For every 0.10V drop under 4.20V/cell doubles the cycle and keeps less capacity. The more the voltage above 4.20V/cell would the less the longevity.
For safety reasons, many lithium-ions cannot exceed 4.20V/cell. While higher voltage boots capacity, exceeding the voltage shortens service life and compromises safety. Figure (5) demonstrate cycle count as a function of charge voltage. At 4.35V, the cycle count of a regular Li-ion is cut in half.
|Figure 5: impact on cycle life at high charge voltages. Higher charge voltages increase capacity but decrease cycle life and compromises safety.
Source: Choi et al. (2002)
For a particular applications, not only setting the most-suited voltage thresholds, it requires a regular Li-ion not to remain at the high-voltage ceiling of 4.20V/cell for prolonged time. The Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. The Li-ion charge turns off the charge current and the battery voltage return to a more natural level.
Technical facts need to be considered when dealing with lithium-based battery
- Environmental conditions, not cycling alone, govern the longevity of lithium-ion batteries. Keeping a fully charged battery at high temperatures is the most dangerous situation, which may cause the battery to explode.
- Battery packs do not die suddenly, but the runtime gradually shortens as the capacity fades.
- Lower charge voltages prolong battery life.
- A normal car battery could be prolonged by lowering the charge voltage when connected to the AC grids. To make this feature user-friendly, a monitoring device should satisfy a long life mode that keeps the battery at 4.05V/cell and provide a capacity of about 80 percent.

Life of primary batteries
Even if never taken out of the original package, disposable (or "primary") batteries can lose 8 to 20 percent of their original charge every year at a temperature of about 20°–30°C. This is known as the "self discharge" rate and is due to non-current-producing "side" chemical reactions, which occur within the cell even if no load is applied to it. The rate of the side reactions is reduced if the batteries are stored at low temperature, although some batteries can be damaged by freezing. High or low temperatures may reduce battery performance. This will affect the initial voltage of the battery. For an AA alkaline battery this initial voltage is approximately normally distributed around 1.6 volts.
Life of rechargeable batteries
Rechargeable batteries traditionally self-discharge more rapidly than disposable alkaline batteries; up to three percent a day (depending on temperature). However, modern Lithium designs have reduced the self-discharge rate to a relatively low level (but still poorer than for primary batteries). Due to their poor shelf life, rechargeable batteries should not be stored and then relied upon to power flashlights or radios in an emergency. For this reason, it is a good idea to keep alkaline batteries on hand. NiCd Batteries are almost always "dead" when purchased, and must be charged before first use.
Although rechargeable batteries may be refreshed by charging, they still suffer degradation through usage. Low-capacity Nickel Metal Hydride (NiMH) batteries (1700-2000 mAh) can be charged for about 1000 cycles, whereas high capacity NiMH batteries (above 2500 mAh) can be charged for about 500 cycles. Nickel Cadmium (NiCd) batteries tend to be rated for 1,000 cycles before their internal resistance increases beyond usable values. Normally a fast charge, rather than a slow overnight charge, will result in a shorter battery lifespan. However, if the overnight charger is not "smart" (i.e. it cannot detect when the battery is fully charged), then overcharging is likely, which will damage the battery. Degradation usually occurs because electrolyte migrates away from the electrodes or because active material falls off the electrodes. NiCd batteries suffer the drawback that they should be fully discharged before recharge. Without full discharge, crystals may build up on the electrodes, thus decreasing the active surface area and increasing internal resistance.

Be prepared to discuss:
- The size of the space available for the battery
- The wattage you calculated above
- Voltage options that work for you and your controlling devices (if necessary)
- The minimum endurance (in hours) that you need the battery to produce.
There are thousands of combinations and technologies available, so now that you are armed with the information you need to provide your battery specialist, selecting the right battery should be much easier. If you would like to discuss your application requirements further, please call to speak to one of our Application Engineers at 864-295-4811.

RC Electric Calculator App for Android
RC Electric Calculator App for Android
RC E-calc Pro - $1.99
It's basically an 8-in-1 calculator for electric powered model airplanes, helicopters, multicopters, cars, trucks and buggy's, if fact anything that uses rechargeable* batteries. (*As long as the voltage is known then any rechargeable battery including LiPo, LiFe, NiCd and NiMh batteries can be used for some calculations). US imperial units and metric units are catered for!
One of the units used for the calculations in the app is the mAh (mill-amp-hours). All batteries have a mAh or Ah rating, this is the capacity of the battery or how much energy is stored. After you've recharged the battery your digital charger will show you how many mAh has been put back into the pack i.e. how much was used. This number is used to calculate a number of things in the app, like expected flight time using 80% of the pack or the average current used during the flight or run.
If you know the current draw of your system additional calculations can be made. In the calculator all the calculations are made "on-the-fly" so no buttons need to be tapped, just input your values and the calculations will be made when enough data is available.
The images should explain how it all works but feel free to ask any questions.
Use RC E-Calc Pro to calculate the following:
- Average Current Used by the aircraft during a flight/run.
- Average Discharge Rate (C-rate) of the LiPo battery during a flight.
- Expected Flight Time using 100% capacity of a battery.
- Expected Flight Time using 80% capacity of a battery.
- Realistic Flight Time using 80% capacity of a battery and 70% average throttle.
- Power in Watts from Volts & Amps.
- Volts from Power & Amps.
- Current in Amps from Power & Volts.
- Static thrust of a propeller in pounds or kilograms.
- Power to Weight Ratio in Watts-per-pound or Watts-per-100gram.
a) Fly (or drive) for 11 minutes and 20 seconds, then recharge your 2200mAh LiPo, when finished your charger states that 1720mAh was returned to the battery.

No battery lasted longer than 1.5 years when used out doors. However, batteries used indoors lasted much longer.
Standard lead acid batteries are supposed to have a life of about 1750 to 2000 cycles if they are charged at 70% utilisation. This means if the drain from a 65-ampere hour battery doesn�t exceed 350 watts it should give a life of about 1750 cycles. In other words towards the end of the cycle it will hold only about 200 watts of useful power. I tried that and measured capacities and I must conclude that in a hot climate like the UAE it will be too much to expect a life of 1000 cycles.
However, I must observe they last much longer at Toronto and standard auto batteries are guaranteed for 72 months plus.
I also kept a record of battery life in automobiles. Maintenance free batteries (even those that come as OEM on autos like Mercedes and made in Germany) do not last longer than 2 years.
Nepal and Afghanistan are much colder than Orissa and batteries definitely will last longer.
Very good make Auto batteries in Orissa do not last three years but even rebuilt batteries used indoors for emergency lighting last up to 5 years.
Ni-Cd batteries are usually guaranteed for 700 to 1000 cycles but I never got more than 100 cycles in the UAE.
There is a misnomer in the Ni-Cd field. Battery prices vary by as much as 1:3. a standard �AA� Battery holds 500 mah. Nickel and Cadmium being costly some manufacturers make them at capacities as low as 100 mah and sell for less.
Zinc Manganese Alkaline batteries are reusable (not rechargeable) but a need a different charger than the ones that charge Ni-Cd batteries. If they are charged beyond 1.65 volts they are likely to leak and fail.
In 1993 I purchased AA alkaline batteries at Bhubaneswar for Rs.18 each so it is no wonder that they are available for Rs. 30 these days.
After Rayovac tried and failed to patent the process the technology became popular. Rayovac claimed 25 recharges from full dead and life�s of about 1750 cycles under certain conditions. However, ordinary alkaline batteries can be successfully reused 10 times over.
A suggestion � pure energy sells rechargeable alkaline batteries and charger available at most Wall marts.

All of the details that we provide with regards to fitment is supplied by the manufacturers and although we do try to keep this updated we do recommend as a final check its worth comparing your original battery with the one shown. With over twenty thousand different batteries its difficult to keep our records as up to date. We do try but new fitments come on stream every week due to the launch of new products.
Mah is the rating which estimates the amount of charge that a battery will hold or how much current it will provide for how long. The higher the this rating the longer the runtime.

One of the most frequently asked questions today by innovators and entrepreneurs looking to design the perfect consumer comfort product is: can I power my gadget with a battery? This post will help you understand the requirements and challenges of using battery power to run your heated device. It all boils down to the questions how big, how hot and how long? Since the choices for batteries are virtually limitless, the purpose of this post is to arm you with the primary information you must have in order to consult a battery specialist, who can help you with your selection.
Let’s review the basics. Heat generation is a function of watt density, ambient conditions and thermal losses (or gains). Watt density is the amount of wattage produced divided by the area producing the wattage, referred to most frequently as watts per square inch.
A real world example: I’ve developed a mobile warming tray and now I want to sell it to Michigan fans for football games. The tray is 8 inches x 8 inches and uses polymer thick film heater technology. I want the heater to get to about 165°F and be able run for about two and a half hours. It will be insulated, have a thermostat and needs to run off a battery. What now?
STEP 1 – Set a target temperature
When it is all said and done, establishing the maximum operating temperature of the item you are designing is the primary driver in evaluating your options. You don’t need to be dead on with this, but the more variables you consider, the more accurately you will be able to predict the outcome. Will there be thermal influences such as insulation, air flow, or large thermal masses adding or taking away from the heater’s capabilities?
For our example, let’s choose a comfortable operating temperature of 60 Degrees
STEP 2 – Estimate the Wattage
After you have determined the temperature you would like to achieve in your device, you can determine the watts per square inch that you will require by conducing some simple tests (refer to our blog post “How to determine the watt density required in my application” for instructions on conducting a simple test for this).
Another way to get a very general idea about what the wattage you may need is to look at the chart below, select a desired operating temperature and note the corresponding watt density. Note that the chart depicts heat output in open air on aluminum, so consider your environment and adjust accordingly.

Maintaining and Troubleshooting Your Laptop Battery
The actual life of a laptop battery will vary with computer usage habits. For
most users, it is not uncommon to experience differences in battery life, of anywhere from just
under one hour to over two hours in each sitting. If you are experiencing shorter battery life
cycles, say 10 to 15 minutes, it may not yet be time to order that new battery.
several factors to take into consideration when determining if the time has come to replace your
battery. This information may also apply to that new battery that you have recently purchased,
that has been giving you fits. The two primary things to consider when troubleshooting battery
problems is Usage Habits and Battery Memory. We will cover both in their complexities in just a
moment, but first, let us take a look at what you should expect from your battery's life cycle.
batteries usually last 1.5 to 2.5 hours.
LiION batteries usually last 2.0 to 3.0 hours.
are average results and the results will vary greatly depending on your system's conservation
settings, the temperature of the room and the climate that you are operating your computer in. As
a general rule, your Lithium Ion battery will last much longer than your standard Nickel Metal
Now let's take a look at the various usage habits to consider when
troubleshooting your laptop's battery. These processes are very similar to the way that your
portable stereo uses batteries ... just think how much faster your stereo eats batteries when you
are playing the CD or the tape deck, as opposed to when you are just playing the radio.
more you use physical devices --- which require more electricity to operate --- the more of the
battery's power you can expect to consume. The devices that create a larger power drain are the
hard drive, the floppy drive and the CD-ROM.
When the computer is able to use its physical
memory resources to store information, the computer will use less of the battery's power, since
the process is mostly electrical in nature. However, when the processes you are using exhaust the
physical memory resources available to your system, the system will turn to virtual memory to
continue the process at hand. Virtual Memory is designed to extend system memory resources by
building a memory swap file on the hard drive, and then transfer needed information between the
hard drive and the physical memory as required.

In the measurement of battery technology, there are four kinds common method (open-circuit voltage measurement, Coulomb calculation, impedance measurement, integrated look-up table method), usually using a combination of methods to one of the main method of supporting the rest of the way computing power.
The first one is the open circuit voltage measurement, this method is that measuring the battery voltage under static values to calculate the remaining battery capacity, but as a result of stationary lithium-ion battery voltage and remaining capacity relation is non-linear, so this method measured valueis not accurate, the vast majority of mobile phone batteries are calculated using this method.
The second one is Coulomb calculation, the method is by measuring the Toshiba laptop battery charge and discharge current, the current value and time value After the calculation of product integration has been carried out by filling the battery into the power and the release of electricity, Coulomb’s method is a accurate method of calculating power.
the third is the impedance measurement, measuring its resistance to get the remaining battery capacity value.
The fourth one is a comprehensive look-up table method, by setting up a related form, the voltage, current, temperature and other parameters, you can query the remaining battery capacity.
tag:ACER AS09D34 Li-ion battery ACER BT.00803.015 Li-ion battery ACER UM09H31 Li-ion battery ACER CGR-B/6C1AW Li-ion battery ACER W83066LC Li-ion battery ACER BT.00903.007 Li-ion battery ACER 3UR18650Y-2-QC236 Li-ion battery ACER UM08B71 Li-ion battery ACER AS10D41 Li-ion battery

Assuming a typical lead-acid, 12 V car battery (typically at 13 V or so fully charged), and that it takes roughly 500 A over 3 seconds to start an engine, how long will it take to recharge the battery at any given charge rate?
Here's my attempt from what I remember about physics:
12.8 V * 500 A = 6400 W
Over 3 seconds that's 19,200 joules.
So, in a perfect world where all the current goes right back in to the battery and whatnot, how long does it take to regain all my joules and put them back in my battery?
Given a 2A charge rate:
14 V (output of charger?) * 2 A = 28 watts
Here's where I'm a little shaky. What's next? Divide the joules by the wattage to get time? Seems like it:
19,200 joules / 28 watts = 11.4 minutes.
That's it? 11.4 minutes at 2 A and all 19,200 joules are back? Seems hard to believe. My charger also has a 10A setting. So that means in about 2.5 minutes, it'll be "recharged".
So, are my assumptions correct? Do you really just use the charging voltage to calculate this, it seems like you would need to put the charging voltage in relation to the battery's capacity/voltage/whatever.

Obviously, the ones with higher amp hour ratings are going to last longer between charges.
Batteries that are larger physically are generally capable of holding more power. This isn’t true across the board, of course, but it is one thing to keep in mind.
If you buy a small battery to fit in your kayak, for example, it isn’t going to give you as much run time as a larger battery would. That said, a kayak-sized trolling motor will probably draw less power from the battery, which may increase its charge life.
There are four main types of marine batteries: lead-acid, AGM, gel, and lithium. Of these types, lithium batteries generally last the longest while lead-acid batteries typically need more frequent recharging.
Of course, it also depends on the quality of the battery. A well-made lead acid battery from an established and trusted brand may perform better than a cheap, low-quality lithium battery.
Regardless of the type of battery, it will lose its ability to hold a charge over time. Older batteries tend to develop internal resistance that makes them more difficult to charge, and when in use, they may discharge more quickly.
If you have an older battery, you can expect that it won’t last as long as it did when it was newer. The problem will only get worse, so it may be a good idea to keep a battery charger on board your boat, just in case the battery dies sooner than you’re expecting.
Some battery types require more maintenance than others, but all types should be properly cleaned and cared for between uses. Stay up to date on any specific maintenance that needs to be done, such as refilling the fluid chamber on lead-acid batteries.
Proper maintenance will extend the life of your battery, thus improving its ability to hold a charge. Batteries kept in proper working order will not discharge as quickly as batteries that are not taken care of.
Operating your trolling motor in extreme temperatures, high winds, and choppy waters will force your battery to work harder, thus causing it to discharge faster.
What’s more, rough weather conditions may cause your battery to be rained on or splashed with sea spray, which can cause damage if the water gets beneath the battery’s outer casing.
Batteries hold a charge for longer in calm waters and mild temperatures.

Figure 2 illustrates the full-discharge and full-charge flags.
Figure 2: Full-discharge and full-charge flags. Calibration occurs by applying a full charge, discharge and charge. This is done in the equipment or with a battery analyzer as part of battery maintenance.
Battery analyzers serve as a valuable tool to calibrate a smart battery. An analyzer fully charges the battery and then applies a controlled discharge that provides the all-important capacity readings of the chemical battery. This discharge measurement is a truer reading than what coulomb counting provides by capturing past discharge events of the digital battery.
How often should a battery be calibrated? The answer depends on the application. For a battery that is in continued use, a calibration should be done once every 3 months or after 40 partial cycles. If the portable device applies a periodic full deep discharge on its own accord, then no additional calibration should be needed.
What happens if the battery is not calibrated regularly? Can such a battery be used with confidence? Most smart battery chargers obey the dictates of the chemical battery rather than the digital battery and there are no safety concerns. The battery should function normally, but the digital readout may become unreliable.
Some smart batteries feature impedance tracking. This is a self-learning algorithm that reduces or eliminates the need to calibrate. If calibration is required, however, several cycles instead of only one may be needed to achieve the same result as with a standard system.
The accuracy between the chemical and digital battery is measured by the Max Error. Max Error stands for “maximum error” and is presented in percentage. A low reading indicates good accuracy, and as the precision diminishes with partial cycles, the Max Error number increases steadily. This supervisory watchdog can be compared to a medical doctor who measures a medical condition by a number.
Some manufacturers recommend calibration at a Max Error of 8 percent; readings above 12 percent may trigger an alarm and 16 could render the battery unserviceable. No unified standard exists to determine what Max Error level requires service or what constitutes an error; every battery manufacturer follows its own recommendation.
The SMBus system provides a wealth of information that includes battery manufacturing date, battery model and serial number, capacity, temperature and estimated runtime, as well as voltages down to the cell levels. It is an engineer’s delight to have all this data in a table, but the fine print may confuse the user more than providing help.

Do you ever wonder about how long does laptop battery last? The laptop once fully charged provides a battery power for 4 to 5 hours. This often gets affected by the number of other factors like what programs are being run on the laptop.
The programs that use memory-intensive and highly demanding programs reduce the life of the battery. Simpler programs like looking at emails or running word programs do not eat a lot of battery life.
This also makes the battery lives longer. When using the laptop reducing the screen brightness and reducing the resolution also have dramatic effects on the run time of the battery.
With age and use the battery slows down after years. The charge capacity decreases as the laptop is used for long. The life of any battery runs for a year or two before it dies out entirely.
In the early stages, the battery that runs 4-5 hours comes down to 1-2 hours and then demands a continuous charge. If the battery is unplugged at the right time, then the overcharging will not ruin the life of the battery.
What Makes a Battery Die?
The way in which the laptop is used makes a lot of impact on the life of the battery. Some habits that affect the battery negatively are :
・Running too many programs can lead to draining the battery. The laptop often runs too many programs, and the problem arises when the programs run in the background when other programs run on the forefront.
・Using the laptop with high brightness. This battery brightness drains all the battery power and reduces the battery life.
・Listening to continuous music when using the laptop. This will not come as a surprise to many that they listen to music when they are working on the laptop. The speaker drains a lot of power from the system that ultimately reduced the battery life.
・Using the apps or letting them run even when not using them. How often do we leave the Wi-Fi and Bluetooth on when they are not in use? These apps eat a lot of power even when running in the background.
・Not using power-saving mode when needed. When it is appropriate, use these modes so that the battery can go into a saving mode and not run out of energy.
・High temperature has a negative effect on the battery. Exposing the battery to extreme heat leads to a major problem. Do not leave the laptop in the charging mode when the not in use. Charge the laptop only when it is close to 0% charging.

18650 Battery Pack Calculator and Planner
Select a cell from the cell database
Use this autocomplete search functionality to find your specific cell in order to pre-populate the values that we have for that cell.
Single cell information
Enter information on a single cell into the input fields to receive results for a single cell. Results will automatically generate every time a value changes and there is enough information to calcualte results.
The C-rate will be used down below at pack level calculations, so make sure you fill this section out.
Pack level information
Enter information related to your up-and-coming pack to get all kinds of information on the pack.
The C-rate, voltage, and capacities from the single-cell step will be used to calculate information in this step. Make sure that you fill out the fields above to get accurate results in this section.
Virtual battery life estimator
This section allows you to get an idea of approximately how long the pack you are building will be able to run.
If you plan on running something that consumes 1000W, you can now figure out how long the pack will last while providing that power.
Pack weight and cell cost
This section estimates the cost and weight of the pack based on cell count, single cell weight, and cost per cell.
The series and parallel information from the above step are used to calculate this information, so make sure you fill out the above step first.

A busy nurse in a hospital, the policeman on duty and the solider in combat has only one question: “Will the battery last for my mission?” Figure 3 illustrates a screenshot of the data stored in an SMBus battery.
Figure 3: Uinversal screenshot of SMBus battery. Data is organized in tables to assist analysis, a format that is less suited for the everyday battery user. Access is by a software tool.
Source: Texas Instrument
Of special interest in terms of battery state-of-health (SoH) is full charge capacity (FCC), coulomb count that is hidden in the table among tons of other information. FCC can be used with reasonable accuracy to estimate battery SoH without applying a full discharge cycle to measure capacity. Best accuracies are achieved if the battery is being cycled with a full charge and an occasional deep discharge. If used sporadically, a deliberate calibration involving a full discharge/charge cycle will be needed from time-to-time to maintain accuracy.
Last updated 2016-09-02
Comments are intended for "commenting," an open discussion amongst site visitors. Battery University monitors the comments and understands the importance of expressing perspectives and opinions in a shared forum. However, all communication must be done with the use of appropriate language and the avoidance of spam and discrimination.
If you have a suggestion or would like to report an error, please use the "contact us" form or email us at: BatteryU@cadex.com. We like to hear from you but we cannot answer all inquiries. We recommend posting your question in the comment sections for the Battery University Group (BUG) to share.

- Disconnect the feeder once the battery is full / at the end of the maintaining period.
How Many Volts is a Motorcycle Battery?
The standard motorcycle battery is listed as a 12V power bank. However, this refers to the current it feeds. The battery itself should have no less than 12.8V when fully charged. Still, the discharge and voltage do not correlate in a linear way. For example, if the voltage drops to 12.5V, it means the cell is half-full and needs recharging.
If the voltage doesn’t fall below 12.0V, it is still operational but should be fed as soon as possible, since further discharging might lead to sulfation and capacity loss. In case the voltage is less than 12.0V, it might decrease the cranking power and hold the charge worse than before. If it drops below 10.8V, the battery could be revived, but most likely, for one cycle only, upon which it becomes non-operational.
How Long does a Motorcycle Battery Last? A Quick Overview
The manufacturers state different periods of service life for their batteries. This depends on the cell type:
- Conventional cells. Last about 3-4 years, 7 if used correctly.
- AGM. Have a longer life, about 5-7 years.
- Gel. Can last up to 10 years.
- Lithium. Can reach as much as 15 years (by advertisement).
The life of the actual battery can differ since many factors affect its operation and period of work:
- Usage. Constant usage prolongs service life.
- Weather. A mild climate without much heat is the most preferable.
- Maintaining. Batteries maintained through the idling period serve longer.
How to Test a Motorcycle Battery Properly?
Testing of the motorcycle battery depends on their types. The following tests can be performed:
- Estimation of specific gravity. This can be done for conventional lead-acid batteries by hydrometer. The power bank should be fully charged before testing. Readings of 1.265-1.280 show a full battery.
- Voltage estimation. Sealed lead-acid and lithium batteries can be tested for voltage level. For that, various appliances are used (voltmeter, conductance tester, etc.)

Lithium-ion batteries have a protection circuit that prevents “abuse” of the battery. This means that, among other things, the battery does not become unusable if it is “overloaded”, but that mechanism does not always work. When the batteries are “asleep” the chargers offer a small boost charge -pulses of very short duration but very high voltage – to activate that protection circuit, and if it is detected that one of the cells begins to charge, the process starts normal. Unfortunately, this mechanism does not always work,
4. How is the state of a battery measured?
This concept of the previous section leads us to another important concept: how to describe the state and condition of a battery. There are several types of ways to present it , but the most widespread is the state of charge (State of Charge, SOC), which is a percentage of the maximum capacity. Another way of expressing it is the depth of discharge (Depth of Discharge, DOD), which is also a percentage of the maximum load: it is usually accepted that 80% of DOD means having entered a deep discharge phase, and this it is dangerous.
Other measures are the voltage of the terminal – it would be with the SOC and the load and discharge current -, the voltage of the open circuit – the one that exists between the terminals of the battery when there is no load applied – and the internal resistance , which varies and depends on the state of charge: as the internal resistance increases, the efficiency of the battery is reduced and the thermal stability is reduced because more and more charging energy is converted into heat. Bad business again.
5. Do not count sheep, count recharge cycles
All batteries of this type have a certain lifespan that is measured in recharge cycles . There is no standard that specifies what constitutes a recharge cycle in a detailed way, but it is usually assumed that a full recharge cycle is applied when we recharge the battery (again, it is not accepted that it has to be fully charged) after being downloaded by below 20%.
The way to count those load cycles varies according to the manufacturers, but Apple gives a good example of how they do it: “You could have used half of your laptop’s load one day and you could recharge it completely.

Smart batteries have internal circuit boards with chips which allow them to communicate with the laptop and monitor battery performance, output voltage and temperature. Smart batteries will generally run 15% longer due to their increased efficiency and also give the computer much more accurate "fuel gauge" capabilities to determine how much battery run time is left before the next recharge is required.
Even if the battery case looks the same, you cannot just upgrade to another battery technology unless your laptop has been pre-configured from the manufacturer to accept more than one type of battery type, since the recharging process is different for each of the three types of batteries.
A battery that is not used for a long time will slowly discharge itself. Even with the best of care, a battery needs to be replaced after 500 to 1000 recharges. But still it is not recommended to run a laptop without the battery while on ac power -- the battery often serves as a big capacitor to protect against voltage peaks from your ac outlet.
As the manufacturers change the shapes of their batteries every few months, you might have problems to find a new battery for your laptop in a few years from now. This is somewhat of a concern only if you anticipate using the same laptop several years from now. If in doubt, buy a spare battery now - before it's out of stock.
New batteries come in a discharged condition and must be fully charged before use. It is recommended that you fully charge and discharge the new battery two to four times to allow it to reach its maximum rated capacity. It is generally recommend that you perform an overnight charge (approximately twelve hours) for this. Note: It is normal for a battery to become warm to the touch during charging and discharging. When charging the battery for the first time, the device may indicate that charging is complete after just 10 or 15 minutes. This is a normal with rechargeable batteries. New batteries are hard for the device to charge; they have never been fully charged and are not broken in. Sometimes the device's charger will stop charging a new battery before it is fully charged. If this happens, remove the battery from the device and then reinsert it. The charge cycle should begin again. This may happen several times during the first battery charge. Don't worry; it's perfectly normal. Keep the battery healthy by fully charging and then fully discharging it at least once every two to three weeks.

(2) The life of a rechargeable phone battery in terms of conversation time, standby time and total service life, will depend on the conditions of use and network configuration. Batteries being considered expendable supplies, the specifications state that you should obtain optimal performance for your phone during the first six months after purchase and for approximately 200 more recharges.
Necessary cookies are essential to the functionality of this website. You may disable these by changing your browser settings, but this may affect how the website functions.
Performance cookies will collect information about how your use the website and allow us to keep improving how our website works.
Functionality cookies enable the website to remember choices that you make and to provide enhanced and convenient functions.

This has been translated into a set of basic battery requirements by USABC:
- 15 years calendar life at 30 °C (recently changed from 35 °C); and
- 5,000 charge-depleting (CD) and 300,000 charge-sustaining (CS) cycles (e.g., microcycles) (75 MWh total energy throughput, for a nominal PHEV-20).
To date, no battery meeting PHEV performance and packaging requirement has been shown to meet the calendar and cycle life requirements, Gross said, although some have come close.
Battery life. For a given chemistry, capacity loss and impedance growth over calendar time will comply with a linear time relation, a square-root time relation, or in-between, Gross said. This can only be determined under controlled test conditions; accelerated testing is used to determine this model fitting.
Probably the most common way [Chrysler] looks at battery calendar life is we do Arrhenius modeling... The Arrhenius models are well done and well understood, its very simple to take this and then say, for example based on some experience with this location, offset them and adjust them for particular solar episodes....this way you can actually start looking at your data, processing it, trying to get some ideas as to how long you are really going to be able to operate this vehicle and meet the end of life requirements.—Oliver Gross
With the derived acceleration factors, you can begin to do simple prediction on calendar life and the effects of operating temperature on life.
Some of their initial results show that operating 3 hours per day with a 10 °C operating temperature above ambient can lower battery life by 5%—which, for the battery pack in that evaluation, would take it to an end-of-life calendar life of just over 15 years for some locations.
Chrysler’s battery use model blends UDDS, HWYFET and US06 cycles to represent multiple use scenarios. Putting this all together (merging calendar life, energy throughput and an operational temperature increase of 10 °C), resulted in product life estimates that vary by location and by miles driven.
Battery packs in use in Los Angeles, Phoenix and Miami had the lowest estimated calendar lives, at 11.8, 11.6, and 11.6 years respectively at 10,000 miles per year.

In the illustrative embodiment, look-up table 500 is selected based on the Δi, the battery chemistry and battery type. The selected look-up table is then accessed using the voltage difference. Since the difference in the currents is known a priori, the data stored in column 508 of the look-up table contains the internal battery impedance, Z, based upon the predetermined Δi. The data stored in column 510 of the look-up table 514 is the precharacterized data relating the remaining battery capacity to the value of Z.
In one embodiment, the determination of the relationship between the internal battery impedance and the remaining battery capacity is based upon remaining battery capacity gathered empirically from batteries while measurements are made of the internal battery impedance. It would be obvious to one of skill in the art that the data must be gathered from a statistically significant number of batteries to produce data having a sufficient confidence interval and accuracy. In addition, it is preferable that the data gathered from batteries operating in an environment similar to the environment in which the batteries are likely to be used. In particular, the batteries need to be tested and the data gathered in an environment having the same temperature as that in which the batteries will be used. This is because certain batteries are sensitive to temperature variations. In particular, the internal impedance of some batteries is dependent upon temperature sensitive chemical reactions within the battery. Where batteries may be used at a variety of ambient temperatures, data should be gathered at multiple temperatures spanning the expected temperature range of the battery.
In an alternative embodiment, a microprocessor may be used in to increase the accuracy of the outputs based upon the data contained within look-up table 500. Such a microprocessor provides for a more accurate determination of both internal battery impedance and remaining battery capacity when there is no data entry corresponding exactly to the voltage or current difference. The process of interpolation is considered to be known to those skilled in the relevant art.
In another embodiment, empirically collected data as described above can be analyzed and a mathematical function derived therefrom. Many different curve-fitting functions or approximation techniques may be used. In one embodiment, a least-squares technique is used to derive polynomial functions approximating the relationship between the remaining battery capacity data and the internal battery impedance. In alternative embodiments, any suitable set of basis functions can be used to derive mathematical functions approximating the relationship between the remaining battery capacity and the internal battery impedance.

There are basically four types of cell phone batteries => Lithium Polymer, Lithium Ion, Nickel Metal Hydride and Nickel Cadmium.
Li-Ion (Lithium Ion) Li-Ion (Lithium Ion)
- Capacity Battery Capacity
1250 mAh 2000 mAh
- Standby Standby Time is the total amount of time that you can leave your is fully charged, turned on and ready to send and receive calls or data transmissions before completely discharging the battery.
Up to 180 Hours Up to 280 Hours
- Talk Time Talk Time is the longest time that a single battery charge will last when you are constantly talking on the phone under perfect conditions, Ambient temperature and highly dependent on the cellular network environment such as the distance to the closest cell network tower.
Up to 5 Hours Up to 9 Hours
- Music Play

A third conventional technique for testing battery capacity, commonly referred to as a battery fuel gauge, is a battery monitoring circuit that measures the current output from the battery during use, and the current input to the battery during charging cycles. The battery monitoring circuit determines the remaining capacity of the battery based on a tally of the cumulative input and output currents. This test is accurate, however, only when proper maintenance has been performed on the battery. For example, NiCd batteries require reconditioning cycles to be performed periodically. These reconditioning cycles return the all the NiCd cells within the battery pack to a full charge. Without the proper reconditioning cycles, the NiCd cells may develop a charge memory or a cell imbalance. A cell imbalance occurs when one cell of a battery pack discharges more quickly than the other cells. As the other cells in the battery pack supply current to the load, the discharged cell will be reverse charged. This reverse charge will decrease the NiCd cell life and, therefore, reduce the life of the battery pack. If the NiCd cells within the battery pack develop a charge memory, the NiCd cells will appear to be at full capacity, but in fact will be charged to only a fraction of their total capacity. Thus, the accuracy of this test is dependent upon the ability to consider the maintenance history of the battery between reconditioning procedures.
What is needed, therefore, is a fast and accurate method and apparatus for determining the capacity of a variety of battery types and chemistries under a variety of conditions.
The present invention is a fast and accurate remaining battery capacity testing system and associated methodology that overcomes the above and other drawbacks of conventional techniques. The present invention determines the remaining battery capacity based on a measured battery impedance and a predetermined relationship between battery impedance and the remaining battery capacity for the battery under test.
In one aspect of the invention a battery capacity tester is disclosed. The battery capacity tester determines remaining battery capacity of a battery coupled to the tester as a function of the present internal battery impedance. In the illustrated embodiments, the tester determines an internal battery impedance by measuring terminal voltages during one or more successive applications of a known load, each load drawing a predetermined constant current from the battery. The calculated internal battery impedance is used to determine the remaining battery capacity based on a precharacterized relationship between internal battery impedance and battery capacity for the battery under test.

Also the impact of low voltage battery is significant on the fuel pump, by casing low fuel pressure, due to slow running fuel pump.
One of the disadvantages of lead-acid battery, when it fully discharged, a significant of chemical changing behaviour occur on lead plate located within the lead battery. A symptoms of low bower battery occur, due to the sulphate layer cover the lead plate that prevent the battery from charging. Therefore, keeping this battery at or near full charge at all the time is crucial.
Approximately, between four to five years is the average battery life in typical conditions. Battery’s power can be decreased up to 50% when the temperature dropped to 20 F degrees, notably the suitable current to start the cold engine is almost twice amps at this temperature. Thus, the impact of varying temperature on batteries is significant.
Ways of checking the battery
There are many ways to determine battery’s conditions, the most accurate one, is using a digital voltmeter, that display battery parameters values as a digital number.
Battery’s voltage is no reliable to determine battery status accurately, as a fully charged battery is a most of the cars is approximately 12.65V. when discharging this battery to 75%, the readying display 12.45V. therefore the most accurate way to determine battery status is by measuring the battery’s energy.
Also, a fully charged battery may not be able to start the engine or even the battery may be defective, as the main concern when starting the engine, is that the battery can deliver a suitable current when applying a particular load on it.
Determine the battery status
Two ways to determine battery status:
- By applying a load testing with a tester that calibrate the load on the battery, which is requires the battery to be fully charged for accurate test results.
- By testing with an electronic (conductance) tester, which does not require a fully charged battery for accurate test results.
How conductance testers works
Conductance tester deliver a frequency signal though the battery to determine the volum active plate area is available to hold and send power. As the battery ages, its conductance decline. Bearing in mind that sorts, opens and other defects also affect conductance. Therefor measuring conductance gives an accurate indication of the battery condition.
Generally many electronic battery testers also determine battery’s Cold Cranking Amp (CCA) capacity, which can be used to estimate the battery’s remaining service life.

If you need to top a cell up, remove the cap and carefully pour in DISTILLED water until the cell is at the right level. Close the caps tightly afterwards. You do not need to add acid, ever. Gel and VRLA batteries do not need to be topped up, and you should NEVER open the vent caps on these types of battery.
- When not using a battery, keep it fully charged. Lead acid batteries must always be kept fully charged when not in use, otherwise the lead plates will quickly sulfate and render the battery useless. Solar panels and wind turbines managed by a charge controller will keep your batteries fully charged without damaging them.
- When using a solar panel that outputs more than 5 watts, you must use a charge controller. This device prevents your batteries from being overcharged. Batteries that are allowed to overcharge will "boil dry" and soon become useless. Overcharging also causes them to vent hydrogen gas into the air, which is explosive. Always use a charge controller.
- When using your batteries, you should avoid discharging them more than 50 percent of their total capacity. Batteries that are regularly flattened completely will only last you a fraction of their possible lifetime. Knowing your batteries' capacity, and how much current you are drawing from it when using an appliance will help you figure out how long you can run everything for.
How much power can a battery store?
On all lead acid batteries, you should find a sticker or a plate with details on it. We are looking for a number followed by the "Ah", which stands for "Amp hours". Let's say your battery is rated at 50Ah. What this means is that if you were to draw a load of 50 Amps from the battery, it would be completely dead in one hour. Or, you could draw one Amp from the battery, and it would last 50 hours. If you were to draw 10 Amps, it would last for five. However, it is important to remember the rule about only using upto half of the batteries capacity. So, if you've got a 50Ah battery, you'll want to stop using things when 25Ah of it's capacity has been taken. If you had two batteries that were the same voltage and had a capacity of 50Ah each, you could wire them together in Parallel and the total capacity would now be 100Ah.

Low-capacity NiMH batteries (1,700–2,000 mA·h) can be charged some 1,000 times, whereas high-capacity NiMH batteries (above 2,500 mA·h) last about 500 cycles. NiCd batteries tend to be rated for 1,000 cycles before their internal resistance permanently increases beyond usable values.
Battery: Charge/discharge speed
Fast charging increases component changes, shortening battery lifespan.
If a charger cannot detect when the battery is fully charged then overcharging is likely, damaging it.
Battery: Memory effect
NiCd cells, if used in a particular repetitive manner, may show a decrease in capacity called "memory effect". The effect can be avoided with simple practices. NiMH cells, although similar in chemistry, suffer less from memory effect.
An analog camcorder [lithium ion] battery
Battery: Environmental conditions
Automotive lead–acid rechargeable batteries must endure stress due to vibration, shock, and temperature range. Because of these stresses and sulfation of their lead plates, few automotive batteries last beyond six years of regular use. Automotive starting (SLI: Starting, Lighting, Ignition) batteries have many thin plates to maximize current. In general, the thicker the plates the longer the life. They are typically discharged only slightly before recharge.
"Deep-cycle" lead–acid batteries such as those used in electric golf carts have much thicker plates to extend longevity. The main benefit of the lead–acid battery is its low cost; its main drawbacks are large size and weight for a given capacity and voltage. Lead–acid batteries should never be discharged to below 20% of their capacity, because internal resistance will cause heat and damage when they are recharged. Deep-cycle lead–acid systems often use a low-charge warning light or a low-charge power cut-off switch to prevent the type of damage that will shorten the battery's life.
Battery life can be extended by storing the batteries at a low temperature, as in a refrigerator or freezer, which slows the side reactions. Such storage can extend the life of alkaline batteries by about 5%; rechargeable batteries can hold their charge much longer, depending upon type. To reach their maximum voltage, batteries must be returned to room temperature; discharging an alkaline battery at 250 mA at 0 °C is only half as efficient as at 20 °C.

I was trying to calculate the recharge capacity of the Lithium ion polymer 3.7v, 2600mAh battery and was using the calculations in the MintyBoost user manual – choosing batteries page (http://www.ladyada.net/make/mintyboost/power.htm), as a guide. I wonder if there is an error in the output calculation line for the 1200 mAh lipoly battery in the “How many recharges will I get?” section.
If the capacity calculation is correct with:
MintyBoost mWh = 3.7V * 1200mAh * 100% = 4440 mWh input
The calculation for the milliAmp hours the mintyboost will output at 5V seems to use the battery capacity for two Sanyo AA NiMH 2700 mAh batteries:
Output mAh @ 5V = 5184mWh / 5 * 80% = 710 mAh output
Shouldn’t the calculation be:
Output mAh @ 5V = 4440mWh / 5 * 100% = 888 mAh output?

If you are tens of micro-amps in an hour, you can reach 1-2 Hao'an.
In this case, for example, 14.8V/2200MAH, 30% of the factory's power of about 600-700MAH is completely discharge for more than a year. If the battery is assembled on the product, then some of the electronics on the product are added. Components may leak faster and take less time. When the power of the lithium battery pack is completely dry, the cell diaphragm paper is completely dried and the electrolyte is completely “0”, and it cannot be activated at all, and it cannot be recharged. Some customers may say that it is not much better to fully charge the battery when you leave the factory. It is really better for this problem, but if the factory power is full, it is very unsafe, so the industry standard is everyone. 30% charged.
Used: When the battery pack is discharged and is protected, that is, the battery is basically discharged (in fact, there is only a little power remaining). In the normal use case, when the lithium battery pack is discharged to the protection voltage, the protection board is automatically turned off. At this time, the lithium battery pack is nearly exhausted, but some of the remaining power is about 5%, and it will be charged when it is used up under normal conditions. Sometimes, when I am busy, I forget that after a few days, I have nothing to do. I basically refilled after half a month and a month. The problem is not big. However, if this is used up, if you put it three or four months without charging it, it will almost be scrapped.
In response to these problems, as long as you do the following, there is no problem.
*: If the new battery has never been used, please do not leave it for too long. Especially if the new battery has not been used, don't throw it for four or five months. If it really can't be released in time, please remember to make up the battery!
Second: If the goods have already been shipped, they need to be indicated to the customer on the product manual. If the new product does not charge for a long time, the battery will fail. If it is used under normal conditions, when the battery is used up, it should be charged in an emergency.

INSTRUCTIONS FOR PROPER CARE AND USE OF YOUR BATTERY
Please follow the instructions included with your battery for proper use, storage and care of your battery to ensure that it will function as needed during a power outage. If you do not store your battery correctly, it may shorten its useful life. Environmental factors such as temperature can shorten your battery’s useful life. We recommend that you store your battery above 41°F and below 104°F.
These batteries are rechargeable. They will not last forever and should be replaced every 5-8 years considering 1-2 full discharges per year. You should periodically test your battery to verify both the operation of the backup battery and its condition.

If you have kids, you probably know this already, but lots of stuff needs batteries. Remote control toys, Wii remotes, laser pointers (well, that is for me), flash lights, even Nerf guns. For me, I have found the best place to pick up batteries is at one of these "dollar" stores. Sure the batteries are cheaper, but are they any good? Who knows. Let's find out.
The first way to look at the quality of a battery is to see how much stored energy is in it. How could you measure this? Well, here is how I did it. I took a battery and connected to a light bulb and let it run for as long as it could. Like this:
With this setup, I can measure both the current ( I ) from the battery and the electric potential ( ΔV ) across the battery. At any given instant in time, the power from the battery will be:
Power tells me how fast the energy is changing, but not the total energy in the battery. In order to find the total energy, I can write the power like this:
If the current and the change in potential were constant for the whole time interval (Δt), this would be a fairly straightforward calculation. Alas, these are not constant. So what do I do? I cheat. If I instead look at a very short time interval, the current and potential do not really change too much. This means that I can reasonably calculate the energy during this short time. Then I just need to do this a whole bunch of times to get the total energy.
Adding up a whole bunch of small pieces is called "an integral". In this case, I won't use calculus to evaluate an integral since I don't know a mathematical function for the power. Instead I will do it numerically with the following formula (by "I will do" I really mean "make a computer do"):
And that is it. The total energy that the battery produced.
Vernier makes both a current and voltage probe for the LabQuest system. Collecting data was fairly simple (even though each battery would take quite some time). Here is the data from LoggerPro (Vernier's software):
This software can calculate both the power as well as integrate to find the total energy. But I am not going to do this. Why?

Internal components must be kept separate, because they can react violently with the air to generate heat and produce fire. Manufacturers overcome this with stringent production methods and safer designs.
There are other battery chemistry alternatives. Rarely seen is nickel chloride batteries, whose main advantage is its robustness and its recyclability, but at a higher upfront cost. Other new battery technologies have emerged in recent years, including ‘flow’ batteries and saltwater based batteries, each with its owns advantages.
To find the appropriately size system, you should know the storage capacity of the battery. But be mindful. Batteries have a total capacity (nominal) and a ‘usable’ capacity. This is because batteries can’t discharge their full capacity without damaging itself. To put in perspective, smartphones may have 16 gigabytes of storage capacity, but only 12 gigabytes is usable because the rest is for crucial software, without which the phone can’t run.
This refers to the rate of electricity the battery can provide (in kW). In essence, a higher value means more electricity can be provided in a given time. There are two parts to output: continuous and peak. Continuous is the rate of electricity the battery can provide, and maximum is the rate the battery can reach for a short period (matter of seconds) during a large demand spike.
For example, your electricity demand will spike if you turn on multiple appliances at the same time. This is important if you are considering going off-grid, because there is no backup power source to meet the demands in your home.
Battery storage, like many things in life, is not perfect. You will not get the same amount of electricity out, compared to what you put in. For example, a 10kWh battery with 85% efficiency will let you draw a maximum of 8.5 kWh.
Knowing how long your battery will last is crucial. The duration of a battery’s working life can be measured in charge cycles or warrantied energy throughput, which is arguably more important.
Batteries will need to be replaced after being charged/discharged a certain number of times. Normally, you will not go through more than one cycle per day if you charge your battery with your solar panel. This means that a battery with a cycle life of 3650 cycles will last 10 years.

Depends on use, and example would be if you use the batteries in an mp3 player consistently day in and out, charging them once or every other day, then you may get a year or two out of them. On the other hand, if they are not used as hard, they could have much more longevity.
• What should I do with my old batteries?
Recycle them at your local recycling center. Major retail chains have drop offs that don't charge to recycle used batteries. Check you local Yellow Pages for listings in your area. Some laptop manufacturers in the past have had exchange programs when sending in old laptop batteries for the new one, be sure to check into this as well if you are replacing your laptop battery. The same applies for cell phones.
No, always go with the recommended battery type for your device. Do not deviate from the manufacturer requirements and recommendations.
Never! Not only will they not recharge, but you take an extreme risk of fire and explosions. Just stay away from this thought altogether.
• Is fully discharging a battery and recharging bad for a battery?
While the Lithium- are not effected by this, it is recommended for the NiCd and NiMh types. Fully charging, then discharging will help with there longevity and achieve maximum storage. However in time they will wear out.
Care for Existing Batteries:
• New batteries normally come in a discharged or barely charged condition. Be sure to read the manufacturers recommendation on charging them for the first time. This is critical to get started off on the right foot with your investment and to get the most life out of them.
• If you don't plan to use the battery for more than a month, remove the battery from the device or charger, then place it is a dry, cool, and clean environment for storage. Rechargeable batteries lose charge when unused. So, when it is installed back into its device, it may require to be recharged back to capacity.
• Keep moisture and excessive extreme heat away from batteries. Heat will cause a battery to explode, potentially causing, bodily harm, burns, fire, or even in some cases death.
• Dropping and physically damaging batteries is really bad, for it can expose the inner cells and acids to the surface. Disregard any damaged batteries.
When purchasing new rechargeable batteries, they can be purchased at just about any retail chain.

Even though I kept them charged with a properly deigned "battery tender", and watched them carefully, they never lasted more than 12 months.
Expensive lesson, but well-learned.
The next common type is the "Deep Cycle"
type. These batteries are designed uses that require a lower current draw for extended periods. Sometimes they're called "motive" batteries, and are used for wheel chairs, golf carts, trolling motors, and solar power storage. Every time I've replaced my car battery I've always replaced it with a deep cycle battery, as there's times I'll run my radio for extended periods without running the engine, and I want to make sure I have enough power left to start the car.
And within the battery types are some sub-classifications depending on the type of construction used.
"Flooded" types have the liquid electrolyte (aka Battery Acid) and removable caps to check the levels. Most of us grew up with this type, and are somewhat familiar with it. I always used distilled water to top off the level, although many sources say that any potable water is OK. Personally, with the cost of distilled water being so low, I could never see using tap water, especially in areas with hard water.
"Valve Regulated Lead Acid" (VRLA) batteries were first seen in the late 1960's, and were marketed as "Maintenance Free" batteries. They used a slightly different chemistry and construction/
"AGM" or Absorbed Glass Mat batteries are newer still, and have a different construction that keeps all the electrolyte in a fiberglass mesh.
And as of 2016 some cars are using Nickle Metal Hydride and Lithium Ion batteries for their power source.
So, with that said, be aware that using old fashioned, flooded construction SLI batteries would work, but the batteries probably won't last as long as you'd like.
Now as to "How Many Batteries Will We Need", we need to look at voltages, and we'll use my trusty SB-310 as our example.
The SB-310 "requires" 185 Volts for the B+, -85 Volts for the Bias, and 6 Volts for the filaments.
Nominal, fully charged voltage for a "12 Volt" automotive battery varies some with the type. We'll go with the current VRLA batteries as they're most common in newer cars.

Try to store your phone in a cool or warm place, and purchase a cell phone case with good ventilation to store it in. And while you may hear otherwise, never store your batteries in the refrigerator.
Know When Your Battery Has Run Dry
No matter how much you care for your batteries, they will run dry. But it will not happen overnight. The amount of time you can leave your laptop or phone uncharged will decrease bit by bit over the months (or years). You won’t notice it at first until you realize one day that it can barely hold a charge at all.
On a notebook it is easy to find how much capacity your battery has left. In Windows open the Command Prompt and type:
This will save a report on your computer showing how much battery capacity is left.
If you have a Mac, then you can find the information in the “Hardware” section of your System Information Window. Note that Apple, like many other electronic companies, tracks battery lifespan by cycle counts. When a battery charges completely, that is one cycle count. The vast majority of MacBooks have a cycle count of 1000, which is when the battery is considered to be consumed. However, MacBooks from 2010 or earlier can have a cycle count of 500 or less.
For your smartphone, outside apps can help a lot. The Battery app for Android or BatteryLife for the iPhone or iPad can tell you what your battery’s lifespan is. Remember that you probably don’t need to replace either a laptop or smartphone battery until the capacity has fallen to around twenty percent, though you can do it earlier.
Plenty More to Do
There is more you can do to keep your battery’s lifespan running longer. Darken your screen display, find power saving modes, and don’t rely on your phone’s GPS so much. We have already covered plenty of battery saving tips for Windows, Mac OS X, Android, Linux and iOS, so do check them out. But above all else, you should keep your devices’ batteries at around room temperature and not fully charged so that they can continue to last over the long run.
But no matter how much work you do to keep your battery alive, they will fade eventually. So while you can keep your three-year-old battery working longer with proper care, check its levels. The last thing you want is to realize out of the blue that your computer or smartphone battery cannot hold a charge at all anymore.

This is pretty straight forward, how big are the batteries? Lead acid batteries don't get much smaller than C-cell batteries. Coin cells don't get much larger than a quarter. There are also standard sizes, such as AA and 9V which may be desirable.
Weight and power density
This is a performance issue: higher quality (and more expensive) batteries will have a higher power density. If weight is an important part of your project, you will want to go with a lighter, high-density battery. Often this is expressed in Watts-hours per Kilogram.
Price is pretty much proportional to power-density (you pay more for higher density) and proportional to power capacity (you pay more for more capacity). The more power you want in a smaller, lighter package the more you will have to pay.
The voltage of a battery cell is determined by the chemistry used inside. For example, all Alkaline cells are 1.5V, all lead-acid's are 2V, and lithiums are 3V. Batteries can be made of multiple cells, so for example, you'll rarely see a 2V lead-acid battery. Usually they are connected together inside to make a 6V, 12V or 24V battery. Likewise, most electronics use multiple alkalines to generate the voltage they need to run.
Don't forget that voltage is a 'nominal' measurement, a "1.5V" AA battery actually starts out at 1.6V and then quickly drops down to 1.5 and then slowly drifts down to 1.0V at which point the battery is considered 'dead'.
Some batteries are rechargable, usually they can be recharged 100's of times.
This guide was first published on Feb 16, 2013. It was last updated on Feb 16, 2013.
This page (How Batteries Are Measured) was last updated on Dec 04, 2021.
Text editor powered by tinymce.

The oxygen in the water and the lead sulfate react together on the positive plates to transform them by and by into lead dioxide, and oxygen bubbles ascend from the positive plates when the response is verging on complete.
Numerous individuals imagine that a battery’s inner resistance is high when the battery is completely charged, and this is not the situation. Looking at this logically, you’ll recollect that the lead sulfate goes about as an encasing. The more sulfate on the plates, the higher the batteries inside resistance. The more resistance possessed by a discharged battery permits it to acknowledge a greater rates of charge without overheating or gassing compared to when there is almost a full charge state of the. When it is close full charge, the remaining sulfate managing the converse substance response is not much. The charge current level which won’t overheat the battery when applied or separate the electrolyte into hydrogen and oxygen is known as the “natural absorption rate” of the battery. Whenever there is abundant charge current of this normal absorption rate, there is overcharging. The battery may overheat, and the electrolyte will bubble. Really, a portion of the charging current is squandered as warmth even at right charging levels, and this wastefulness makes the need to put more amp hours once more into a battery than were taken out.
To what extent will My Battery Last?
There are numerous things that can bring about a battery to fall flat or radically abbreviate its life. Something or other is permitting a battery to stay in a mostly discharged state. We discussed sulfate shaping on the surface of the battery’s plates amid release, and the sulfate likewise frames as a consequence of self-release. Sulfate additionally frames rapidly if the electrolyte level is permitted to drop to the point that the plates are uncovered. On the off chance that this sulfate is permitted to stay on the plates, the gems will become bigger and solidify till they get to be difficult to evacuate through charging. In this way, the measure of accessible surface range for the substance response will be forever diminished. This condition is called “sulfation,” and it forever lessens the battery’s ability. A 20 amp hour battery may begin performing like a 16 amp hour (or littler) battery, losing voltage quickly under burden and neglecting to keep up adequate voltage amid wrenching to work the motorcycle’s ignition framework.

The reason that you need to follow along with the aforementioned steps is because your battery thrives on consistency. Now you need to consider replacing the battery. If you’re storing the battery for many months or more. It is however advised that you get a spare battery and carry it with you if you’re going to be spending extended amounts of time on the street. You’re going to need no less than a 14-amp battery so as to run your equipment for those hours per day you specified. It’s always advised to opt for an original battery. One is they make batteries with higher capacity.
Batteries make life much more easy. There is absolutely no true means to tell just how long a single battery will last as even two batteries on both identical systems may be used at several rates based on the settings and applications that are being run. At this stage, normally, they are discarded. A universal battery is only a bigger version of the conventional laptop battery, and can power almost any laptop. Incredibly vital as the appropriate rechargeable battery is going to be the suitable battery charger.
Life After Disposing of Laptop Batteries
You are able to charge batteries individually, and that means you’re not restricted to only charging them in pairs as with a number of other chargers. To illustrate what happens every time a battery becomes discharged, in the following article, a lead-acid battery like an automobile battery or golf cart battery was used. The battery hasn’t witnessed the type of advance which other devices have. An extremely old and pre-owned battery can take more than 20 ounces of distilled H20! Now, let your previous battery take its rest and search for battery replacement.
Batteries have come a ways through history. The battery is currently ready for charging. Homemade batteries can likewise be built from different vegetables and fruits. They are commonly made of common items found around the house.
Always ensure the battery is recharged whenever possible after it gets fully discharged. The lithium-ion battery is quite popular in a broad selection of household electronics. You won’t wish to ruin terrific batteries utilizing a poor charger.

Rechargeable Batteries: Which One to Buy, Differences?
Batteries are used everyday in any portable electronic device. So far, there is no other energy source on the the market yet to power our energy hungry equipment. They are in devices from calculators to laptops. We depend on them dearly, however as a consumer know very little about them. Below is a list of the different common types of batteries that are used in consumer electronics.
• NiCd: Nickel is found commonly in household batteries such as AA, AAA, 9v, etc. While this type of battery holds a charge longer, they don't typically have the voltage that is needed for power hungry electronics such as it's counterpart .
• NiMh: Nickel Medal Hidride is also found in common household batteries as the , however they have a much higher and needed voltage output for electronics with the trade of a quicker power drainage. NiMh is the recommended battery of choice for devices such as CD players, mp3 players, wireless devices such as mice, keyboards, etc.
• -Ion: These batteries are used in laptops, cell phones, iPods, iPhones, etc. These batteries have a long lasting energy drain and don't discharge as quickly while sitting idle. Unfortunately, they also don't come in standard flavors such as the AA & AAA type batteries. So you will likely see these batteries found in proprietary devices such as listed above.
Common Battery Questions:
• Do rechargeable batteries ever lose the ability to hold a charge?
Yes, in time, they will hold less of a charge due to the chemicals inside not reacting as they once did when they were new.
• My batteries don't seem to last long in my device is there anything I can do to lengthen the life of the battery?
All rechargeable batteries have a mah rating (Milliampere Hour). The higher the rating on the battery, the longer it will last. Be warned however, if your battery charger is only rated to be able to charge up to say a 1800mah, and you buy 2500mah batteries, your charger will either take a much longer time to charge the batteries or not charge them at all. Be sure to have an adequate battery charger before or while purchasing new rechargeable batteries.
• How long do rechargeable batteries last?

The battery is now calibrated. The very first thing you will want to is make certain you have batteries in the remote control. A faulty battery may cause a severe fire. It’s possible for you to buy bigger cell batteries that will provide you with longer battery life.
In the event the battery gets hot enough to ignite the electrolyte, you’re likely to obtain a fire. Better still, you can get another battery that’s a larger-capacity than your initial battery. To begin with, it is possible to always purchase another battery. Refurbished things are usually inexpensive laptop batteries that are sold at a part of the price of a new laptop battery.
After the battery has charged to a particular level, it is going to get started charging at a regular rate again. NiCad and NIMH batteries have a normal shelf life of a couple decades. Put simply, a battery will be specified in amp-hours. Laptop batteries are sometimes not straightforward to discover, but the internet is a wonderful resource. Many laptop batteries begin to fail within a couple years. In the event the laptop battery may not be recharged, it’s going to need to be replaced. Most individuals buy laptops Laptop Battery only because they need to be portable.
With a new battery and assorted problems fixed, the laptop is prepared to serve. It is dangerous to continue to keep your laptop on all day long because once you do so, you are likely additionally to keep it plugged in for that duration to stop the battery from draining out. When you have identified the specific reason, switch off the laptop, disconnect the wires and remove the battery, to steer clear of shock. If you intend to fix the laptop yourself, be sure that the replacement parts are genuine and match your component. Before you opt to get a 3D laptop, there are a few essential things you must evaluate.
Laptops are designed to be portable. Learn what others say about the length of time a laptop should last. Leaving your laptop in an auto in the summer is risky.
The Benefits of How Long Do Laptop Batteries Last
You may try an easy and effortless DIY restoration. As stated earlier, laptop screen repair can be carried out even at home, you only need to be aware of the basic techniques on replacement. Most people may not do so, and it’s a good idea for them to go to a computer mechanic instead.

Do you have a pile of AA rechargeable batteries in your drawer? Some are old, some are new, but which sets would you bring with your camera on your next trip, and which ones are past their useful life? I like using rechargeable batteries, but I’m certain that some of them are not living up to the stated capacity on the label.
So how good are those batteries? Simple battery testers measure the voltage, but that’s not what we need – we want to find the overall capacity of the battery. How long will a battery last from the time it’s fully charged to the time that the “low battery” indicator comes on your device?
You can see this in action in a video in the last step of this instructable.
Step 1: This is a job for a microcontroller
That is a quick solution to the problem, but it involves watching a voltmeter for a few hours. That’s no fun at all. With a microcontroller, like the good old AVR chip, we can make a rechargeable battery tester that does the work for us. My tester puts AA batteries through a discharge test and reports the capacity in milliamp-hours (mAh) so you can compare battery capacity.
The tester can test multiple cells individually, and display the results on an LCD.
The tester discharges the battery while monitoring the voltage of the batteries. When the low threshold is reached, that cell is done it disconnects the load from the battery. When all tests are complete a series of beeps alerts the user. The tester identifies the type of battery by its initial voltage allowing both NiCd and NiMh batteries to be tested.
The design is based on the ATMega168 microcontroller, which has 6 A/D converters on the chip, so these will be used to read the battery voltages and determine the load current. Since each battery will require two A/D converters per cell, the maximum number of cells is three.
I built two of the testers, first using an Arduino board as a development system, and then a standalone device that will be more compact, and free up the Arduino for other projects.

So now that you know what factors affect battery life, is there any way to extend your battery’s run time per charge? How can you make your battery last longer?
- Running the motor at low speed: As noted above, there’s rarely any need to keep your trolling motor on the highest setting, as it will drain your battery more quickly.
Keep the motor at a slower speed as much as possible. The amp draw will be lower, so your battery will last longer.
- Going out in calm waters: Rough weather and water conditions make it necessary to run your motor at higher speeds, which puts an extra strain on your battery. If you want to get the most time out of a charge, stick to calm waters on mild days.
- Using the battery only for the trolling motor: Again, the more you draw power from the battery, the sooner that power will be used up.
If you have other devices on board that require battery power, it may be best to have a separate battery for them. Use your trolling motor battery only for your trolling motor if you want it to last as long as possible.
How Long Will a 12V Battery Last With a Trolling Motor?
It will depend on all of the factors listed above, so it’s impossible to say exactly.
To estimate how long it may last, compare the battery’s amp hour rating against the motor’s amp draw.
For example, the Minn Kota Edge 70 trolling motor has a max amp draw of 42 amps; if you were using the Renogy Hybrid Gel 100Ah battery , you would divide 100 by 42 for an approximate run time of 2.4 hours at top speed.
What is the Longest Lasting Marine Battery Used With a Trolling Motor?
Generally speaking, the longest-lasting marine batteries are good-quality lithium phosphate batteries. These batteries discharge more slowly and can be discharged much deeper than other types of batteries.
Again though, it largely depends on amp hours vs. amp draw, along with many other factors. Regardless of the type of battery you choose, it’s important to select a high-quality one and then take care of it.
How long a marine battery powers a trolling motor depends on many factors. There are various battery sizes and capacities, trolling motors with a variety of amp draw needs, and many conditions in the environment that can affect how quickly a battery discharges.

We've discovered a truth in life. When you have four or more vehicles inyour fleet, your biggest problems become empty gas tanks and deadbatteries. Gas is an easy one; you can siphon it directly from the lawnmower or the neighbor's boat. But what about the battery? Why does itdie, and what kills it? Knowing the answers to these questions will helpyou understand and hopefully prevent a belly-up battery.
In simple terms, a battery consists of a lead-coated electrode calledthe anode and a lead-oxide coated electrode called the cathode thatcombine to form a cell. There are six of these cells in a 12-voltbattery, each contributing about 2.1 volts. They are immersed in asolution of sulfuric acid and distilled water called an electrolyte andconnected through a system of grids and plates in a series that ends atthe positive and negative terminals. As the acid eats away at themetals, the cathode releases positively charged ions into theelectrolyte solution. Since it retains the electrons, it becomenegatively charged. Similarly, the anode reacts to the positivelycharged electrolyte and releases electrons and becomes positivelycharged. This movement of electrons creates a polar difference betweenthe oppositely charged plates in each cell and creates a difference orvoltage between the two terminals. When you hook up your battery cables,it creates a circuit and allows electrical current to flow. Simpleenough.
When the French dude Andre Ampere gave us ways to measure this electriccurrent flowing through a wire, the amount of storage capacity in abattery soon became rated in terms of the ampere hour (A.H) using acommon scale, such as the 20-hour rate of discharge. For example, a 100A.H rated battery will discharge below a useable level (10.5 volts) in20 hours with a load of 5 A (5 A x 20 hours = 100 A.H). Obviously, mostbatteries are rated below this, but we used an easy number forillustration purposes. If that 100 A.H battery had a 2.5A draw (like adome light) it would drop below 10.5 volts very quickly (2.5 A x 40hours = 100 A.H).
To perform diagnostics, you'll need more than a voltmeter.

Help Me Choose: Battery
|When choosing a laptop battery, it's important to consider how your laptop is used:|
Today’s laptops typically feature two kinds of batteries: user replaceable, which can be easily and instantly switched out with a spare battery as needed, and built-in batteries, which are not user replaceable.
User-replaceable batteries are made of Lithium-ion cells and the number of cells inside a battery determines its size, weight and life between charges. A cell is essentially a smaller battery that is packaged with and connected to other cells to form one large battery. Generally, the greater the number of cells, the more power, weight and size a battery will have.
Laptops with thinner designs, such as the XPS™ and Inspiron™ z series often include built-in batteries. These batteries are often made of Lithium-ion polymer, but also has the extra benefit of fitting into nontraditional shapes. This shape flexibility is instrumental in optimizing laptop design for thinness.
Finally, it’s important to note that battery life is always subject to demands and usage. For laptops that include a user- replaceable battery which is used for extended periods away from an outlet, you might want to consider purchasing a second battery for your laptop from Dell.com. For laptops with built-in battery batteries, a travel adapter or a second power adapter that stays in the backpack can help maintain productivity when you are on the go.
Dell typically notes either the number of cells and/or the watt-hour (WHr) of a battery. More cells (e.g. 6-Cell vs 4-Cells) or higher WHrs on the same system under the same operating conditions will generally deliver longer battery run time.
Battery life is how long your battery will last between charges. Battery pack lifecycle is how often a battery can be recharged before its charge capacity starts to degrade (e.g. when a fully charged battery is reduced to 60% of the original battery charge capacity.) This reduction of charge capacity in turn leads to a significantly reduced battery life. The reduction in charge capacity is normal on all rechargeable batteries.
Extending battery life
The easiest way to get the best battery life out of your Dell laptop is to select one of the pre-configured power plans, such as power saver or balanced by right clicking on the battery symbol in the bottom right corner (or system tray).

If you plan on braving the elements, it would be a good idea to have an extra battery or a battery charger on board, so you don’t end up stranded.
A larger, heavier boat will take more power to push through the water than a small, lightweight boat. More draw on the battery will lead to a quicker discharge.
If you have a larger boat, it’s a good idea to invest in a battery with a higher amp hour rating. A large boat will be able to support the additional size and weight, and you’ll be able to spend more time out on the water, doing what you love.
If you are using a single battery for more than just your trolling motor, it will discharge more quickly because multiple sources will be drawing from it.
For example, if you’re running your trolling motor and fishfinder off the same battery, neither device will last as long as it would on its own. Both are drawing from the battery simultaneously, so the battery will run out of power sooner than it would power only one device.
How Can I Calculate the Battery Run Time on a Trolling Motor?
There is no way to consider all of the factors discussed above; in other words, you cannot accurately predict how long your battery will last on a given outing. But you can give yourself a rough estimate with a few simple calculations.
To estimate how long your battery would last under ideal conditions, divide the battery’s amp hour rating by the maximum amp draw of the motor.
For example, say you have a 100Ah battery and a trolling motor with a max amp draw of 50 amps. 100 divided by 50 equals 2, so the battery would last for about two hours with the trolling motor drawing the maximum number of amps.
Of course, you won’t necessarily be using the trolling motor at top speed the whole time. Maybe you leave your trolling motor on slow or medium speed and the amp draw is about 20. 100 divided by 20 equals 5, so you could expect your battery to last about 5 hours.
For a more in-depth discussion on the topic, check out this helpful article from Newport Vessels.
Again, it’s important to remember you won’t always be running at maximum amp draw, and you can’t factor in other conditions such as water and wind conditions or battery age. Dividing amp hours by amp draw only gives you an estimate.
Can I Make the Battery Last Longer?

This app will then calculate that the average current draw for the flight was 9.11 amps, the discharge rate was 4.1C and you used 78% of the rated capacity of the battery. (Img #1)
b) How long can you fly your plane safely? It is recommended to fly using only 80% of the capacity of LiPo batteries to maximize their longevity so using the 9.11A average from the example above, the full throttle current draw (you will need to measure this) is 16A, input 2200mAh and 16A into the app and it'll calculate that you should be able to fly (at FULL throttle) for 6 minutes 36 seconds until the battery is 80% depleted or for 8 minutes 15 seconds (also at FULL throttle) until it is 100% depleted. (Img #2)
A "Realistic" flight time for a plane is also calculated which works out to be 11 minutes and 47 seconds using 80% capacity and 70% average throttle, very close to the actual flight time in the first example.
For helicopters and multicopters the flight time is very dependant on what style of flight, but you can use the calculator to calculate the expected flight time in a hover.
Future plans: Add wing loading, cubic wing loading calculator, + suggestions?
Disclaimer: The formulas used in these calculations come from various internet sources, with some variations added from my own experience. Your results may vary! While a lot of effort was put into ensuring accuracy, this app is not intended to be professionally accurate.
Comments & suggestions very welcome.
New version is finally up on the Play Store. (link)
One of the new things is working out your likely run/flight time from how much mAh is returned to the battery after a flight.

These values are the average for all time rates between 1 hour and 8 hours." This statement implies that the information is valid for duty cycles up to 8 hours. For discharge durations longer than 8 hours, the user will need to obtain validated appropriate correction factors from the manufacturer. Note, preliminary data from one vendor indicated that the electrolyte temperature during a 72 hour discharge decreased by a couple of degrees F. It appears that at the low discharge rate, the I2R heating was less than the heat needed by the slightly endothermic chemical reaction during the discharge to maintain temperature. The temperature correction factors for duty cycle durations may need to be modified for duty cycle durations significantly longer than 8 hours. IEEE Std 535-2006 8.2 states, “This procedure will age the entire cell to the predominant aging failure mode, which is based on the failure of the positive plates."
The basis of IEEE Std 535-2006 8.2 was the destructive examination of cell plates that were tested at the 8 hour rate. The documentation of the results of destructive examination is available for viewing at the vendors who have previously qualified cells per IEEE Std 535-2006. The available vendor data available indicates that the ampere hours discharged at the 72 hour rate to 1.75 vpc is in the range of 115% of the ampere-hours discharged at the 8 hour rate to 1.75 vpc. For discharge durations greater than 8 hours where the ampere-hours discharged is greater than the rated 8 hour ampere hours, the cell manufacturer will need to demonstrate that there are no other significant failure modes or reduced life due to higher sensitivity due to known failure modes. IEEE Std 535-2006 8.2.2(h) states "Life expectancy of batteries is not affected by two deep discharges per year. Therefore, the above procedure will qualify the battery for the equivalent of two performance discharge tests per year, average, over the qualified life of the battery." In order to meet the requirements of IEEE Std 535-2006, applications with duty cycles durations over 8 hours that discharge more than the rated 8 hour ampere-hours will need to demonstrate that the battery cells can meet the basis statement in 8.2.2(h).
Clause 5 of IEEE Std 535-2006 is reproduced below for reference.
“5.

- Battery History, Technology, Applications and Development. MPower Solutions Ltd. Retrieved 19 March 2007.
- Borvon, Gérard (10 September 2012). "History of the electrical units". Association S-EAU-S.
- "Columbia Dry Cell Battery". National Historic Chemical Landmarks. American Chemical Society. Retrieved 25 March 2013.
- Dingrando 665.
- Saslow 338.
- Dingrando 666.
- Knight 943.
- Knight 976.
- Terminal Voltage – Tiscali Reference Archived 11 April 2008 at the Wayback Machine.. Originally from Hutchinson Encyclopaedia. Retrieved 7 April 2007.
- Dingrando 674.
- Dingrando 677.
- Dingrando 675.
- Fink, Ch. 11, Sec. "Batteries and Fuel Cells."
- Franklin Leonard Pope, Modern Practice of the Electric Telegraph 15th Edition, D. Van Nostrand Company, New York, 1899, pages 7–11. Available on the Internet Archive
- Duracell: Battery Care. Retrieved 10 August 2008.
- Alkaline Manganese Dioxide Handbook and Application Manual (PDF). Energizer. Retrieved 25 August 2008.
- Dynasty VRLA Batteries and Their Application Archived 6 February 2009 at the Wayback Machine.. C&D Technologies, Inc. Retrieved 26 August 2008.
- USBCELL – Revolutionary rechargeable USB battery that can charge from any USB port. Retrieved 6 November 2007.
- "Spotlight on Photovoltaics & Fuel Cells: A Web-based Study & Comparison" (PDF). pp. 1–2. Retrieved 14 March 2007.
- Battery Knowledge – AA Portable Power Corp. Retrieved 16 April 2007. Archived 23 May 2007 at the Wayback Machine.
- "Battery Capacity". techlib.com.
- A Guide to Understanding Battery Specifications, MIT Electric Vehicle Team, December 2008
- Kang, B.; Ceder, G. (2009). "Battery materials for ultrafast charging and discharging". Nature. 458 (7235): 190–193. Bibcode:2009Natur.458..190K.

This means that if a component fails, the whole system has to be replaced.
Each system is patented, so if spare parts are not available will be very expensive adapt the measure from one system to another.
The output power and therefore, the performance is limited by the strength of the chain and sprocket. Standard pinions and chains were designed to human transmission through pedaling, which means that the amount of mechanical energy that can be added is relatively small.
Because of this, maintenance of the drive chain will increase, including all gears and pinions.
Batteries are electrochemical components and have their own, say, “personality”. It is almost impossible to find two identical behavior batteries. Although two people the same model are purchasedelectric bike at the same time, they can have completely different experiences with their batteries.
We have studied the whole theory on batteries (that can keep one busy for a long, long time), but the most useful information has come from our customers. Often, the information provided by laboratory tests can not replace it emerges from the experience of end users with their batteries.
The industry of electric bicycle has been waiting to become an important enough to allow more efficient technologies batteries are offered at reasonable prices sector. This is already beginning to happen.
A battery is not only a solid piece, is a collection of “cells”. The cells are complete units electrolyte with an anode, a cathode and produce electricity from a chemical reaction.
Each type of cell has a nominal voltage. For example, NiMH (nickel metal hydride) is about 1.2 volts per cell, and thus need a lot of cells combined to obtain the voltage used in an electric motor. Thus, 30 cells would get approximately 36 volts, thus obtaining a useful voltage.
How the measured capacity of a battery?
Usually when someone asks about the capacity of a battery, is looking for basically two things: (1) the amount of energy stored in the battery cells (? How far I can go); and (2) what current cell rate (how much power and how fast?) are discharged
The amps are the most common to describe the amount of stored electricity in the cells form. The ability of a cell in ampere / hour (Ah) is also full battery capacity in Ah. A cell 7 Amp is 7 Ah to 1.2 volts.

To do this, I will get a package of batteries, store a few in the refrigerator, store a few at room temperature and store a few in my car (these nice Maryland summers should provide me with enough heat to do the job).
Best rechargeable batteries 2018
I recommend you go to this website in the following order (some concepts build off prior sections):
1. The Device
2. The Experiment
3. The Results
The device I used for this project is a West Mountain Radio Computerized Battery Analyzer (CBA) [available from West Mountain Radio]. The CBA connects to your computer to download the data and control the device. You connect the batteries to the CBA for testing. The CBA then puts a constant load (current draw) on the battery. This is similar to using a light bulb connected to a battery to determine how long it lasts, but with the CBA, I can determine how far I want the battery to discharge to and have a nice, constant current draw to get more accurate results (and nice graphs as well).
For a little background in electronics:
Volts [V] à The potential for electricity (Ex: A 9V battery has the potential for producing 9V)
Amps [A] à The amount of electricity being consumed (Ex: A 100W household light bulb consumes 1A)
Watts [W] à The energy of electrical work (Ex: A light bulb running at 110V and consuming 1A has the energy of 100W)
To calculate the values
Volts x Amps = Watts Watts ÷ Volts = Amps Watts ÷ Amps = Volts
Amp Hours [Ah] à How many hours the battery will last with a 1A draw (Ex: 2Ah battery will last 2 hours with 1A draw OR a 2Ah battery can last 1 hour with a 2A draw).
Ok, so now that I have explained the device and the math involved; now on to how I actually progressed through the experiment.
I only used AA batteries because I found them the cheapest to work with (don’t forget, I had to finance this myself).
I set my CBA to assume the batteries all had 1.5V (They were anywhere from 1.55V to 1.65V, but are all labeled 1.5V).

If you can grasp the basics you will have fewer battery problems and will gain greater battery performance, reliability, and longevity. I suggest you read the entire tutorial, however I have indexed all the information for a quick read and easy reference.
A battery is like a piggy bank. If you keep taking out and putting nothing back you soon will have nothing.
Present day chassis battery power requirements are huge. Look at today's vehicle and all the electrical devices that must be supplied. Electronics require a source of reliable power. Poor battery condition can cause expensive electronic component failure. Did you know that the average auto has 11 pounds of wire in the electrical system? Look at RVs and boats with all the electrical gadgets that require power. I can remember when a trailer or motor home had a single 12-volt house battery. Today it is standard to have 2 or more house batteries powering inverters up to 4000 watts.
Average battery life has become shorter as energy requirements have increased. Life span depends on usage; 6 months to 48 months, yet only 30% of all batteries actually reach the 48-month mark. A Few Basics The Lead Acid battery is made up of plates, lead, and lead oxide (various other elements are used to change density, hardness, porosity, etc.) with a 35% sulfuric acid and 65% water solution. This solution is called electrolyte which causes a chemical reaction that produce electrons. When you test a battery with a hydrometer you are measuring the amount of sulfuric acid in the electrolyte. If your reading is low, that means the chemistry that makes electrons is lacking. So where did the sulfur go? It is resting to the battery plates and when you recharge the battery the sulfur returns to the electrolyte.

If you need more information right now, you may find quick, specific answers to your battery-related questions at the
Battery University website.
In my next column I'll cover classifications, general specifications, and terminology. Until then, please post any questions or comments below.

Subscribe to Blog via Email
© Mark Biegert and Math Encounters, 2019. Publication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mark Biegert and Math Encounters with appropriate and specific direction to the original content.
DisclaimerAll content provided on the mathscinotes.com blog is for informational purposes only. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The owner of mathscinotes.com will not be liable for any errors or omissions in this information nor for the availability of this information. The owner will not be liable for any losses, injuries, or damages from the display or use of this information.
Tag Archives: battery
I live in a cold climate -- so cold that under certain circumstances we can freeze our lead-acid batteries (Figure 1). A customer who lives in my region called recently and was wondering if I thought any of his batteries would have frozen over the winter. A number of his Internet service subscribers have vacation homes that are unoccupied over the winter. All of these vacation home owners turn off their AC power for the winter. Since all of our Optical Network Terminals (ONT) are connected to Uninterruptible Power Sources (UPS), they will begin operating off of their battery when the AC power goes away. If the home owner does not disconnect the battery, the ONT will run discharge the battery. This is important because a discharged battery will freeze -- a charged battery will not freeze. A battery that has been frozen is very likely a dead battery. Continue reading
Derivation of the Output Power Equation The output power equation (Equation 3) is really a restatement of Newton's law of cooling. Equation 3 states the battery's steady-state power dissipation is a linear function of the battery's temperature and the ambient … Continue reading

2 is a block diagram of one embodiment of the battery capacity tester illustrated in FIG. 1;
FIG. 3 is a block diagram of one embodiment of the constant current sink illustrated in FIG. 2;
FIG. 4 is a block diagram of one embodiment of the battery characterizer of the present invention;
FIG. 5 is a schematic view of the look-up tables used in one embodiment of the present invention;
FIG. 6 is a flow chart of one embodiment of a method of practicing the present invention; and
FIGS. 7A and 7B are a flow chart of another embodiment of a method of practicing the present invention.
The present invention is a battery capacity testing system and associated method that determines the remaining battery capacity based on a measured internal battery impedance and a predetermined relationship between battery impedance and remaining battery capacity for the battery under test. In the illustrative embodiments described herein, the system measures the battery terminal voltage during one or more successive applications of a known load, where each load draws a predetermined constant current from the battery. The remaining battery capacity is then determined based on a predetermined relationship between the internal battery impedance and the remaining battery capacity of the battery.
FIG. 1 is a block diagram of a battery capacity tester for determining remaining battery capacity of a battery under test. The battery under test 102 (battery 102) is electrically connected to the battery capacitor tester 104 at positive connection 108 and negative connection 110. In one embodiment, a temperature sensor 112 provides a signal indicative of battery temperature 114 to the battery capacity tester 104. This sensor can be any temperature sensor now or later developed that senses directly or indirectly the temperature of the battery 102. Battery capacity tester 104 generates a remaining battery capacity 106 in accordance with the present invention. In one embodiment, tester 104 is implemented in a battery powered device. In such an embodiment, battery 102 is typically installed in, and provides internal power to, the battery powered device (not shown). In one exemplary application of the present invention, the battery powered device is a portable defibrillator. As will become apparent from the following description, the portable defibrillator can be used with many different types of rechargeable and non-rechargeable battery chemistries and battery types produced by different manufacturers.
FIG. 2 is a block diagram of one embodiment of battery capacity tester 104.