How long will a power station run a CPAP?
A CPAP is one of the best things to run on a power station because it draws little power, but it runs all night. A typical machine uses roughly 30 to 60 W. Adding a heated humidifier can push that to 90 W or more, so check your machine’s label or manual for the real number.
The table assumes an 8-hour night and 87% inverter efficiency, and shows nights on a 1,000 Wh battery with no other devices.
| CPAP draw | Battery energy per night | Nights on 1,000 Wh |
|---|---|---|
| 30 W | about 276 Wh | about 3.6 |
| 40 W | about 368 Wh | about 2.7 |
| 60 W | about 552 Wh | about 1.8 |
| 90 W (heated humidifier) | about 828 Wh | about 1.2 |
How to stretch the battery
- Turn off or turn down the heated humidifier. It uses far more power than the blower itself.
- Use a DC power cord if your CPAP supports one. It skips the inverter loss.
- Keep a reserve. Plan to use no more than 80–90% of the battery’s rated capacity.
- Recharge during the day with solar or a wall outlet when power returns.
Important
Don’t rely on a runtime estimate alone for medical equipment. Talk to your doctor or equipment supplier about a backup plan, and test your setup for a full night before you need it.