Can a portable power station run a CPAP?
Short answer: Yes. A CPAP without the heated humidifier uses about 30–50 W, so a 1,000 Wh power station runs a 40 W machine for roughly 20 hours on its AC outlet, two to three nights. With the humidifier and heated tube on (around 90 W), the same station lasts about 10 hours. Running it from the DC outlet with the maker's DC cable adds about 10%.
Runtime by power station size
Calculated with our runtime calculator: 85% efficiency through the AC inverter, 95% through a DC converter, battery run to empty.
| Power station | 40 W, AC | 40 W, DC | 90 W (humidifier on), AC | 90 W, DC |
|---|---|---|---|---|
| 256 Wh | 5.4 h | 6.1 h | 2.4 h | 2.7 h |
| 512 Wh | 10.9 h | 12.2 h | 4.8 h | 5.4 h |
| 1,024 Wh | 21.8 h | 24.3 h | 9.7 h | 10.8 h |
| 2,048 Wh | 43.5 h | 48.6 h | 19.3 h | 21.6 h |
At 8 hours a night, a 40 W machine on a 1,024 Wh station lasts 2.7 nights on AC and 3.0 on DC.
Find your CPAP's real draw
The power supply brick says something like "90 W". That is its maximum, reached only with the humidifier and heated tube at full. The machine's manual lists typical consumption at a given pressure; most fall between 30 and 60 W without humidification. The most reliable number comes from a plug-in watt meter over a whole night: divide the kWh it shows by the hours.
Making it last longer
- Turn off the humidifier and heated tube. They often use more than the blower itself.
- Use the DC cable for your model instead of the AC outlet: it skips the inverter's losses, and the inverter's own idle draw (5–15 W) on top.
- Recharge during the day from solar panels, a car's 12 V outlet or a generator, so the station starts each night full.
Calculate for your machine and station
Safety. If you depend on a CPAP or other powered medical equipment, tell your electric utility: many keep a medical-needs list and notify those customers before planned outages. Ask your equipment supplier about a backup plan.