Wh
Units & Measurements abbreviation · Engineering Unit
| Stands for | Watt-hour |
|---|---|
| Categories | Units & Measurements |
Wh stands for Watt-hour, an engineering unit abbreviation.
Energy equal to one watt sustained for one hour, or 3,600 joules. Laptop, power bank and e-bike batteries are rated in Wh, a better measure of stored energy than mAh because it accounts for voltage.
Example: Airlines allow power banks up to 100 Wh in carry-on bags without approval.
Usage notes
FAA and IATA rules allow lithium batteries up to 100 Wh in carry-on luggage, those from 100 to 160 Wh with airline approval, and nothing larger in the passenger cabin; spare lithium batteries are banned from checked bags. To convert, multiply mAh by voltage and divide by 1,000: a 20,000 mAh bank at 3.7 V holds 74 Wh.