Ah to kWh Calculator
Convert Ah to kWh from the battery voltage: kWh = Ah × V / 1,000. Formula, worked example and a table of typical values for 12 V to 48 V banks.
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Estimate only. Not engineering or safety advice. Check the result against the applicable standard and the equipment data, and have a competent engineer review it before it is relied on. Terms of use.
Open in the calculator with these values
Formula
Worked example
| Input | Value |
|---|---|
| Battery capacity | 100 Ah |
| Nominal voltage | 48 V |
- Wh = mAh × V / 1000 = 100,000 mAh × 48 V / 1000 = 4,800 Wh
Typical values
| Battery capacity (Ah) | Energy (kWh) |
|---|---|
| 10 | 0.48 |
| 50 | 2.4 |
| 100 | 4.8 |
| 150 | 7.2 |
| 200 | 9.6 |
| 300 | 14.4 |
Other inputs are the same as in the worked example above.
Assumptions
- Nominal (mid-discharge) voltage, not the full-charge voltage
- Constant voltage over the discharge
Cells in series add voltage (3 Li-ion cells = 11.1 V) and keep the cell capacity; cells in parallel add capacity and keep the cell voltage. Use the pack voltage. Rated energy is not usable energy: depth of discharge, converter losses and temperature reduce it.
Frequently asked questions
How do I convert Ah to kWh?
Wh = mAh × V / 1000; mAh = Wh × 1000 / V. Worked example: Battery capacity 100 Ah, nominal voltage 48 V gives 4.8 kWh.
What do I need to enter?
Enter battery capacity, nominal voltage and energy. Leave blank the value you want to find, and the form solves for it. Change the unit of a value with its selector and the result stays the same.
Why do I need the voltage to convert Ah and Wh?
Ah is charge (current × time) and Wh is energy (power × time). They are linked by the battery voltage, so one cannot be converted to the other without it.
Which voltage should I use for a battery bank?
Use the nominal voltage of the whole bank. Batteries in series add voltage (four 12 V batteries make 48 V) and keep the Ah; batteries in parallel add Ah and keep the voltage. The result is rated energy, not usable energy: depth of discharge, inverter losses and temperature reduce it.
How accurate are the results?
Every figure comes from the same tested engine as the Elecmetric calculators and is meant for estimating. Check design values against the standard and the equipment data you work to.
Related
Next steps in a design: Joules to VoltskW to kWhEnergy Unit Converter
Opposite direction: kWh to Ah
Also see: kW to kWh kWh to kW kWh to Watts Watts to kWh
Formula guides: Battery Capacity ConverterBattery Formulas: Capacity and RuntimeBattery Pack Formulas: Series and Parallel
All 78 conversionsmAh to Wh and Wh to mAh in Elecmetric