Ah to Wh Calculator
Convert battery capacity between amp-hours (Ah) and watt-hours (Wh) at 12V, 24V, 48V or a custom voltage.
Result
1,200 Wh
100Ah × 12V
Formula
Watt-hours = Amp-hours × Volts. So a 100Ah battery at 12V stores 100 × 12 = 1,200Wh. The reverse: Amp-hours = Watt-hours ÷ Volts.
Why this matters
Ah ratings alone can't be compared across different voltage systems — a 100Ah battery at 24V stores twice the energy of a 100Ah battery at 12V. Watt-hours is the true, comparable measure of stored energy, which is why product specifications and this site's calculators primarily work in Wh.
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Frequently Asked Questions
How many watt-hours is a 100Ah 12V battery?+
100Ah × 12V = 1,200Wh rated capacity. Usable capacity will be somewhat lower depending on battery chemistry — see the Battery Runtime Calculator for usable capacity by chemistry.
Why do some batteries list 12.8V instead of 12V?+
12.8V is the typical nominal voltage of a 4-cell LiFePO4 battery, often rounded to '12V' for compatibility labelling with traditional 12V lead-acid systems. Use the more precise voltage (e.g. 12.8V) for the most accurate Wh conversion if your battery specifies it.
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