Work out amp hours to watt hours instantly with clear inputs, formula shown and shareable results.
Watt-hours equal amp-hours times voltage, which is why amp-hours alone cannot be compared across different battery voltages. A 100 Ah 12 V battery holds 1.28 kWh; a 100 Ah 48 V battery holds four times that.
Energy conversion
Wh = Ah x V; usable Wh = Wh x depth of discharge
Electrical results are planning estimates only. Verify against the applicable wiring rules (IEC 60364, BS 7671, NEC or local code) and have all installation work designed and checked by a qualified electrician.
Historical convention from lead-acid systems at a fixed 12 V. It is meaningless for comparison unless the voltage is stated too.
Nominal voltage for energy content — 12.8 V for a 4S LFP pack, 3.7 V per lithium-ion cell — not the fully charged voltage.