Battery Capacity Converter — 4 Units, Free & Instant
Convert between Battery Capacity units. Choose from 4 different units including Milliamp-hours, Amp-hours, Watt-Hours.
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All Units
| From | Watt-Hours (Wh) |
|---|---|
| Milliamp-hours (mAh) | 0.0037 |
| Amp-hours (Ah) | 3.7 |
| Watt-Hours (Wh) | 1 |
| Kilowatt-Hours (kWh) | 1000 |
mAh, Wh and the 3.7-volt convention
Battery capacity has two everyday languages: milliamp-hours (mAh) on powerbanks and phones, and watt-hours (Wh) on laptops, tools and airline rules. They connect through voltage — Wh = mAh × V ÷ 1000 — and the industry convention is the Li-ion nominal cell voltage of 3.7 V. That makes 10,000 mAh = 37 Wh and 26,800 mAh ≈ 99 Wh.
The airline limits
Aviation rules are written in Wh: up to 100 Wh (≈27,000 mAh) batteries fly in carry-on without approval, 100–160 Wh needs airline approval, and above 160 Wh is not allowed on passenger aircraft. Spare batteries and powerbanks must travel in the cabin, never in checked luggage — which is exactly why the biggest mainstream powerbanks stop at 26,800 mAh.