Can a power station run a CPAP machine?
Short answer
Yes, easily. A CPAP without a heated humidifier uses about 30 to 60 W, so a 500 Wh power station lasts about one to two nights and a 1,000 Wh unit about two to three. Turning on the heated humidifier and heated tube can double or triple the draw, which cuts those numbers roughly in half.
Why the humidifier matters so much
The blower in a CPAP needs very little power. The heated humidifier and heated tubing are what raise consumption. A machine that uses 40 W on its own can draw 90 W or more with both heaters on in a cold bedroom. During an outage, turning the humidifier off or down is the single biggest way to stretch runtime.
Your machine's power supply shows its maximum rating, which is usually far above what it actually draws. For a real number, check your machine's manual or measure it with a plug-in watt meter for a full night.
Runtime by power station size
Nights assume 8 hours of use per night and 85% usable battery energy on the AC outlet. Running from a DC adapter adds roughly 10 to 15%.
| Power station | No humidifier (40 W) | Humidifier low (60 W) | Humidifier and heated tube (90 W) |
|---|---|---|---|
| 256 Wh 300 W output | 0.7 nights | 0.5 nights | 0.3 nights |
| 512 Wh 600 W output | 1.4 nights | 0.9 nights | 0.6 nights |
| 1,024 Wh 1,800 W output | 2.7 nights | 1.8 nights | 1.2 nights |
| 2,048 Wh 2,400 W output | 5.4 nights | 3.6 nights | 2.4 nights |
| 3,600 Wh 3,600 W output | 9.6 nights | 6.4 nights | 4.2 nights |
For your exact appliance and power station, use the runtime calculator.
Use DC power if you can
A CPAP's power brick converts 120 V AC to low-voltage DC. When you plug that brick into a power station, the station first converts its battery DC to AC, and then the brick converts it back. Each step wastes energy. Most major CPAP makers sell a DC power cord or converter that plugs into a 12 V car-style socket, which most power stations have. That skips both conversions.
If you depend on a CPAP or other medical device, talk to your equipment supplier or doctor about a backup plan. Many US utilities also run medical baseline or life-support registration programs; enrolling can get you advance notice of planned shutoffs.
Recharging for longer outages
A 100 W solar panel in good sun can put back roughly 300 to 500 Wh in a day, enough for one or more nights without the humidifier. On cloudy days expect much less. A car charging cable is a slower backup.
Frequently asked questions
How many watts does a CPAP use?
Most CPAP machines use 30 to 60 W without a heated humidifier. With the humidifier and heated tube on, many draw 60 to 100 W or more.
Can a 300 Wh power station run a CPAP overnight?
It is borderline. At 40 W for 8 hours you need about 320 Wh, and a 300 Wh unit delivers only about 255 Wh on AC. A DC cord and a lower pressure setting help, but a 500 Wh unit is the safer choice.
Is it safe to run a CPAP from a power station?
Yes. Power stations with pure sine wave inverters produce clean power suitable for CPAP machines. Check that your model has a pure sine wave inverter.
Sources and method
Runtime figures assume 85% of battery capacity reaches AC appliances and typical US appliance ratings. See exactly how we calculate. Found a mistake? Tell us and we will fix it.