How many times can a power station charge a phone or laptop?
A lot. A typical phone battery holds about 15 Wh, a tablet about 30 Wh and a laptop about 60 Wh. Charging loses roughly a fifth as heat, so a full charge draws about 18, 35 and 70 Wh. The table assumes the station’s AC outlet at 85% efficiency.
| Station | Phone (~18 Wh) | Tablet (~35 Wh) | Laptop (~70 Wh) |
|---|---|---|---|
| 300 Wh | 14 | 7 | 3 |
| 500 Wh | 23 | 12 | 6 |
| 1,000 Wh | 47 | 24 | 12 |
| 2,000 Wh | 94 | 48 | 24 |
Use the USB ports
Plugging a phone or laptop into the station’s USB-C ports skips the conversion to AC and back, which usually gets you 10 to 20% more charges than using the wall charger in an AC outlet.
Check your own device: its battery size in watt-hours is usually printed on the battery or in the spec sheet. Phones list milliamp-hours instead; multiply by 3.85 and divide by 1000 for watt-hours.
See small power stations on Amazon
Figures assume 85% efficiency on AC and typical draws. The label on your appliance, or a plug-in power meter, gives the exact number; enter it in the calculator.