How much energy is in that battery?
Batteries are usually quoted in milliamp-hours, which is meaningless without a voltage. In watt-hours they can actually be compared.
74% of a home battery
10 kWh is more than 6 of the 9 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| AA battery | 0.00278 kWh | 3,600× | 2.8 Wh |
| phone battery | 0.019 kWh | 526× | About 19 Wh |
| laptop battery | 0.0661 kWh | 151× | |
| power tool battery | 0.09 kWh | 111× | |
| power bank | 0.1 kWh | 100× | 100 Wh — the airline cabin limit |
| e-bike battery | 0.5 kWh | 20× | |
| home battery | 13.5 kWh | 0.741× | 13.5 kWh |
| electric car battery | 75 kWh | 0.133× | 75 kWh |
| grid battery unit | 3,305,556 kWh | 1/330,556 | A 3.3 MWh container |
Worth knowing
- The 100 Wh airline cabin limit is why power banks cluster just under 27 000 mAh at 3.7 V — that is exactly 100 Wh.
- An electric car battery holds as much energy as 4 000 phone batteries, or about 8 litres of petrol’s worth after efficiency losses.
Frequently asked
How do I convert mAh to Wh?
Multiply by the voltage and divide by 1 000. A 5 000 mAh phone battery at 3.85 V is 19.25 Wh. Comparing mAh across different voltages is meaningless.
Why can I only take a 100 Wh battery on a plane?
Lithium cells release their energy very fast in a thermal runaway. 100 Wh is the threshold above which airlines require approval, and 160 Wh the outright limit in the cabin.