WattWise

What size power station for a CPAP machine?

A CPAP is one of the most common reasons people buy a power station. The trick: the machine itself sips power — it's the heated humidifier that drains batteries.

Nights of runtime by capacity

With the heated humidifier and heated tube off, most CPAPs draw about 30–60W and use roughly 320 watt-hours per 8-hour night. Assuming ~85% usable capacity:

Power stationUsable energyNights (humidifier off)Nights (humidifier on)
300 Wh~255 Wh~0.8 nightunder 1 night
500 Wh~425 Wh~1.3 nights~0.5 night
1000 Wh~850 Wh~2.5–3 nights~1 night
2000 Wh~1700 Wh~5 nights~2 nights
💡 Battery-saving tips: turn off the heated humidifier and heated hose on battery (they can triple consumption). If your CPAP has a 12V DC input, use the power station's DC output to skip inverter losses and gain ~15% more runtime.

Quick recommendation

One night (emergency/outage): 300–500Wh. A weekend of camping: 1000Wh. A week off-grid: 2000Wh, ideally with a solar panel to recharge each day. Any modern unit's output easily covers a CPAP's low wattage — capacity is what matters here.

See 1000Wh options →

Running other things too (phone, lights, a fan)? The full power station size calculator adds it all up for you.

FAQ

What size power station do I need for a CPAP?

With the humidifier off (~320Wh/night): 500Wh ≈ one night, 1000Wh ≈ 2–3 nights, 2000Wh ≈ a long weekend.

How many nights will a 1000Wh power station run a CPAP?

About 2–3 nights with the humidifier off; closer to one night with it on.

Should I use AC or DC output?

Use DC if your CPAP supports it — you skip the inverter and gain ~15% runtime. Otherwise AC is fine.

When you buy through links on this page we may earn a commission, at no extra cost to you. Estimates only — check your CPAP's manual for exact power draw. This is not medical advice.