Medical & sleep

What Size Power Station Do I Need for a CPAP?

Simple math for one night or several, using the numbers on your own machine.

By The Backup Power Guide · Written by a solar installation & maintenance professional · Updated October 31, 2026

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Short answer: Many CPAP machines draw roughly 30–60 W without the heated humidifier, so an 8-hour night is about 250–500 Wh. A 1,000 Wh power station typically covers around two nights; turning off the heated humidifier and heated tube can extend runtime. Always check your machine's label or manual, and talk to your provider about backup power.

Step 1: find your CPAP's watts

Look on the power supply brick or in the manual for watts (or volts × amps). The heated humidifier and heated tubing can add a lot, so note both numbers if listed.

Step 2: do the math

Watts × hours of sleep = Wh per night. Divide by about 0.85 to cover inverter losses. Example: 40 W × 8 h ÷ 0.85 ≈ 376 Wh per night. Our calculator includes a CPAP line you can edit.

Step 3: stretch the runtime

Turn off the heated humidifier and heated tube if your provider says that is OK for you.
Some machines offer a DC power cord from the manufacturer, which can avoid inverter losses; check what your model supports.
Recharge during the day from the wall when power returns, or from solar panels.

Models to consider

Most output in the 1kWh class

Anker SOLIX C1000 Gen 2

1024 Wh
2,000 W output (3,000 W peak)
LFP
10 ports
Recharges at 1,600W in 49 min (listing)

Check price on Amazon →

Expandable mid-size backup

EcoFlow DELTA 3

1024 Wh
1,800 W output
LiFePO4
500W solar input
Full AC charge in 56 min (listing)
Expandable up to 5kWh
4,000 cycles to 80%

Check price on Amazon →

Most capacity in the 1kWh class

BLUETTI AC180

1152 Wh
1,800 W output (2,700 W peak)
LiFePO4
0-80% in 45 min (listing)
8 outlets

Check price on Amazon →

Frequently asked questions

Can a 500 Wh power station run a CPAP all night?

Often yes for a single night without the heated humidifier, if your CPAP uses around 30–50 W. Check your machine's watts and do the math with your sleep hours.

Does the humidifier really matter?

Yes. Heated humidifiers and heated tubing can draw much more power than the CPAP motor itself, which can cut runtime significantly.

Is this medical advice?

No. This is general sizing math. Ask your doctor or equipment provider about using your CPAP on backup power.