Electrical units and conversion

Battery kWh to Ah converter

Divide energy by the system voltage to get charge. The answer only means something alongside the voltage it was calculated at.

How do you convert kilowatt-hours to amp-hours?

Multiply kilowatt-hours by 1,000 to get watt-hours, then divide by the nominal system voltage. A 10 kWh battery is 10,000 Wh, which is 208.3 Ah at 48 V but 833.3 Ah at 12 V. Both describe the same stored energy — the amp-hour number changes only because the voltage changed. This is exact arithmetic on nominal DC capacity.

Your inputs

Capacity in kilowatt-hours

Nominal battery voltage

Use the nominal voltage printed on the battery, not the resting or charging voltage.

Common system voltages

208.3 Ah

at 48 V nominal

10.00 kWh at 48 V nominal. Amp-hours are only comparable at the same voltage.

Exact given your inputs

Amp-hours: 208.3 Ah
Voltage: 48.0 V
Watt-hours: 10,000 Wh
Kilowatt-hours: 10.00 kWh

This is nominal DC energy

The conversion itself is exact arithmetic, but the result is the energy stored on the DC side at nominal voltage. Usable energy at an AC outlet is lower once depth of discharge and inverter efficiency are applied.

Method

10.00 kWh × 1000 = 10,000 Wh
10,000 Wh ÷ 48 V = 208.3 Ah

Assumptions

Nominal voltage is used throughout; real pack voltage varies with state of charge.
No depth-of-discharge limit, inverter loss or temperature effect is applied.
Lead-acid capacity ratings assume a specific discharge rate — a 100 Ah lead-acid battery does not deliver 100 Ah at high current.
No depth of discharge, reserve or inverter efficiency is applied here — Ah × V ÷ 1000 and kWh × 1000 ÷ V are exact inverses of each other.

What can change the result?

Which voltage you use — nominal, resting or charging voltage give different answers
Battery chemistry, since usable depth of discharge differs sharply between lead-acid and lithium
Discharge rate, which reduces effective lead-acid capacity (Peukert effect)

Common capacities at common system voltages

The conversion is exact arithmetic; amp-hours are rounded to one decimal for display.
Kilowatt-hours	System voltage	Watt-hours	Amp-hours
5 kWh	48 V	5,000 Wh	104.2 Ah
10 kWh	48 V	10,000 Wh	208.3 Ah
10 kWh	51.2 V	10,000 Wh	195.3 Ah
13.5 kWh	48 V	13,500 Wh	281.3 Ah
5 kWh	24 V	5,000 Wh	208.3 Ah
2.4 kWh	12 V	2,400 Wh	200.0 Ah

Why higher voltage systems are specified this way

For the same stored energy, a higher system voltage means proportionally fewer amps. That matters because current, not energy, determines cable thickness and heat: delivering 3 kW at 12 V requires 250 A and very heavy conductors, while the same 3 kW at 48 V needs about 62 A. This is why almost all modern home storage runs at 48 V or higher and why comparing amp-hour figures across different voltages tells you nothing useful.

When you specify a pack, give both numbers — for example “10 kWh, 51.2 V, 195 Ah”. Any one of them alone is ambiguous.