kWh to Ah Calculator
Convert kilowatt-hours (kWh) to amp-hours (Ah) using battery voltage: Ah = kWh × 1,000 ÷ V. Plan solar storage, home batteries and EV packs.
CAPACITY
416.67 Ah
IN mAh
416,667 mAh
FORMULA
Ah = (kWh×1000)/V
💡 How to Convert kWh to Ah
To convert kWh to Ah, multiply the kilowatt-hours by 1,000 to get watt-hours, then divide by the battery voltage. This tells you the amp-hour rating a battery bank needs at your system voltage to store a given amount of energy.
kWh to Ah formula
Example: 5 kWh at 48 V → 5,000 ÷ 48 = 104.2 Ah
Worked examples
- 5 kWh off-grid bank at 12 V: 5,000 ÷ 12 = 416.7 Ah, which is why larger systems move to higher voltages.
- Same 5 kWh at 48 V: 5,000 ÷ 48 = 104.2 Ah, a quarter of the current and much thinner cables.
- 13.5 kWh home battery at 51.2 V nominal: 13,500 ÷ 51.2 = 263.7 Ah.
kWh to Ah table
| kWh | 12 V | 24 V | 48 V | 51.2 V | 400 V |
|---|---|---|---|---|---|
| 1 | 83.3 | 41.7 | 20.8 | 19.5 | 2.5 |
| 2.5 | 208.3 | 104.2 | 52.1 | 48.8 | 6.2 |
| 5 | 416.7 | 208.3 | 104.2 | 97.7 | 12.5 |
| 7.5 | 625 | 312.5 | 156.2 | 146.5 | 18.8 |
| 10 | 833.3 | 416.7 | 208.3 | 195.3 | 25 |
| 13.5 | 1,125 | 562.5 | 281.2 | 263.7 | 33.8 |
| 15 | 1,250 | 625 | 312.5 | 293 | 37.5 |
| 20 | 1,666.7 | 833.3 | 416.7 | 390.6 | 50 |
The 400 V column shows why electric-vehicle packs, which run at several hundred volts, have modest amp-hour ratings despite storing tens of kWh.
Why higher-voltage systems are used for bigger batteries
For the same energy, doubling the voltage halves the amp-hours and halves the current. Lower current means smaller cables, smaller fuses and lower resistive losses, which is why systems above a few kWh usually run at 24 V or 48 V rather than 12 V.
Rated versus usable energy
The result is the battery's rated energy. You get less in practice because:
- Depth of discharge: lead-acid batteries are commonly kept above 50% charge to protect their life, while LiFePO4 batteries are often used to 80–100% of capacity.
- Inverter losses: converting battery DC to household AC typically loses about 5–15%.
- Discharge rate: lead-acid capacity is usually quoted at a slow 20-hour rate; drawing current faster yields fewer amp-hours (the Peukert effect).