Amp hour calculator how to#

Here’s how to calculate its amp hours: 1280Wh ÷ 12.8V = 100Ah

You look at the battery specs and see that it has a voltage of 12.8 volts and a capacity of 1280 watt hours. Let’s say you have the following LiFePO4 battery. To calculate a battery’s milliamp hours, divide its watt hours by its voltage and then multiply by 1,000.įormula: battery milliamp hours = battery watt hours ÷ battery voltage × 1,000Ĭalculator: Watt Hours to Milliamp Hours Calculator Example Small batteries - such as those found in phones, tablets, and battery packs - more commonly express their battery capacity in milliamp hours. To calculate a battery’s amp hours, divide its watt hours by its voltage.įormula: battery amp hours = battery watt hours ÷ battery voltageĬalculator: Watt Hours to Amp Hours Calculator For battery banks with multiple batteries wired together, we’ll also calculate your battery bank’s voltage. And if you’ve entered your battery capacity in amp hours, we’ll calculate your battery’s watt hours. If you’ve entered your battery capacity in watt hours, we’ll calculate your battery’s amp hours. Click “Calculate Battery Capacity” to get your results. We’ll use this number to calculate the length of your parallel strings.ħ.

Amp hour calculator series#

For instance, if each of your series strings has 4 batteries in it, you’d enter the number 4. If your batteries are wired in a series-parallel configuration, enter the number of batteries wired together in each series string. If you’ve selected the series-parallel option, a field will appear asking for the length of your series strings.Ħ. The series-parallel option is only available if you’ve entered a number of 4 or greater in the Quantity field. The wiring options are series, parallel, and series-parallel. If you have multiple batteries in your battery bank, select how they’re wired together. If you enter 2 or more, a field will appear asking how your batteries are wired together.ĥ. If you’re calculating the capacity of 1 battery, you’d just enter the number 1. Enter the number of batteries you have in your battery bank.

Amp hour calculator full#

For some battery types, such as lead acid batteries, you can’t use their full capacity without damaging them and shortening their lifespan.Ĥ. If you select a battery type, we’ll estimate your battery’s usable capacity. Optional: Select your battery type from the list. If you have a 12V battery, you’d enter the number 12.ģ. For instance, if you have a 1200Wh battery, you’d enter the number 1200 and then select “Wh” from the list of unit options.Ģ. The unit options are milliamp hours (mAh), amp hours (Ah), watt hours (Wh), and kilowatt hours (kWh). Enter your battery’s capacity and select its unit from the list. But this is the easiest way of getting a pretty good idea of how long your battery will last.Battery voltage: How to Use This Calculatorġ. Other factors may affect the length of service of the battery such as the battery’s age, number of charging and discharging cycles, temperature, etc.

This particular battery will power your system for approximately 58 hours. Using the same equation in the first example we get:Īmp Hour (Ah) = Current (I) x Discharge Time (T)

Now for the example below, we will find how long a battery will last given its AH rating and the current needed by the system to function.Ī 12V AGM 35Ah Battery is used to supply power to a system with a current draw of 0.6 Amperes. Therefore, this battery would have an amp hour rating of :Īmp Hour = Current (I) x Discharge Time (T) We will take our previous example for consistency, thus:Ĭurrent (I) = 10 amperes Discharge Time (T) = 15 hours Or if we have the amp hour rating of the battery, we can compute how long the battery will last while supplying a certain current. We can compute the amp hour rating of a battery by multiplying the current ( amperes) by the discharge time (hours). The Amp Hour also has sub-units like the MilliAmpere-Hour (mA-h or mAh), and the MilliAmpere-Second (mA-s) which is the unit of measure used in X-ray diagnostic imaging and radiation therapy. Now we look deeper into another factor which greatly affects our batteries, the Ampere Hour or Amp Hour rating.Īn Amp Hour (Ah) is the amount of current a certain battery can supply for a certain period of time. In our previous post, we focused on the definition of a battery’s Voltage and how it affects the battery’s performance.