Choosing a Power Station for a CPAP Machine
Updated 2026-09-24
A power station is one of the simplest ways to keep a CPAP running during a power outage or on a camping trip. The main thing that decides how many nights you get is whether you use the heated humidifier.
This guide is general information about power use, not medical advice. If you depend on CPAP or other medical equipment, talk to your provider and your equipment supplier about a backup plan.
How much power a CPAP uses
Exact numbers depend on your machine, pressure setting and mask. Typical ranges:
| Setup | Typical draw | Per 8-hour night |
|---|---|---|
| CPAP, humidifier off | 30–60W | 240–480Wh |
| CPAP, heated humidifier on | 70–110W | 560–880Wh |
| CPAP + heated tube + humidifier | 90–140W | 720–1,120Wh |
Your machine's power supply brick lists a maximum wattage (often 65–90W). Actual use is usually well below that when the humidifier is off.
Use DC if you can
Plugging the CPAP's normal power brick into a station's AC outlet means converting DC battery power to AC, then back to DC inside the brick, losing energy both times. Most CPAP manufacturers sell a DC power cord that plugs straight into a 12V car-style port. Skipping the conversion can add 10–20% more runtime, sometimes more.
Check that the station's 12V port provides a regulated 12V output. Most current models do, and your CPAP maker's DC cable instructions will list what it needs.
Nights per charge
Assuming 45W with the humidifier off, over an 8-hour night:
| Station capacity | Nights (AC outlet) | Nights (DC cable, approx.) |
|---|---|---|
| 256–288Wh | ~0.7 | ~1 |
| 768Wh | ~1.8 | ~2 |
| 1,024Wh | ~2.4 | ~3 |
| 2,048Wh | ~4.8 | ~5+ |
With the humidifier on, divide those numbers by roughly two.
What to look for
- Capacity for at least two nights with a margin, so a second outage night isn't a gamble.
- A UPS or pass-through mode so the station switches over automatically if the grid fails while you sleep. Most current models support this; switch-over times of 10–30ms are fine for CPAP.
- Quiet operation. Some stations run cooling fans even at low loads. Reviews usually mention it.
- Solar input if you camp for more than a couple of nights.
Compact stations are enough for camping without the humidifier. For home backup, a 768Wh–1kWh station gives you breathing room (and runs a fridge too). Try your exact setup in the runtime calculator — CPAP with and without humidifier are both listed.