What Size Power Station Do I Need for a CPAP?

This guide helps you size a portable power station for a CPAP or similar breathing-support device during an outage or while camping. It is general information about electricity and batteries, not medical advice. Your device’s manual, your equipment provider and your clinician decide what is right for you, including whether to rely on a battery at all.

What should you check on your CPAP first?

Find your device’s power specifications in its manual or on its label: the power supply’s output voltage and current, and the typical and peak consumption in watts. Note which accessories you use, such as a heated humidifier or heated tube, because they add to the draw. If you are unsure, ask your equipment provider.

As an example, ResMed lists the AirSense 11 at about 56.1 W typical and 73.2 W peak consumption with its 24 V power supply. Other models and settings differ, so use your own figures in place of these.

How do you calculate CPAP runtime?

Multiply the station’s capacity by 0.85 for inverter losses, then divide by the device’s watts. This is the same assumption as our runtime calculator.

At 56.1 W for 8 hours, the device uses 56.1 x 8 = about 449 Wh. The battery has to supply 449 / 0.85 = about 528 Wh. At the 73.2 W peak figure it is 586 Wh at the outlet and about 689 Wh from the battery. Treat the peak as a worst-case planning number.

How long will 300 Wh, 1 kWh and 1.15 kWh stations run a CPAP?

Station	Capacity	Usable at 85%	At 56.1 W	At 73.2 W
Jackery Explorer 300 v2	288 Wh	244.8 Wh	4.4 h	3.3 h
Jackery Explorer 1000 v2	1,070 Wh	909.5 Wh	16.2 h	12.4 h
BLUETTI AC180	1,152 Wh	979.2 Wh	17.5 h	13.4 h

A 300 Wh class station is a stopgap for part of a night. A 1 kWh class station covers one night with margin and two nights at the typical figure with almost no margin. Because we are working from published specifications and not tests, leave a margin of your own, and recharge between nights if you can. See the power station list for other sizes.

Should you use the DC adapter?

Where the manufacturer supports it, running the device from a DC supply avoids the inverter loss. ResMed, for example, sells a DC/DC converter for the AirSense 11 with a 12 V or 24 V input and 24 V output. Use only the adapter your device’s manufacturer approves, and check that the station’s DC port can supply its input current. We do not state a DC runtime here because the converter’s own efficiency is not published in the sources we used.

What else should you plan for?

Check that the station’s surge and continuous ratings are well above the CPAP load, which is easy for the models above. Keep the station charged before a storm, and have a backup plan agreed with your equipment provider. For household-scale backup, see can a portable power station power a house, and for how fridge loads compare, see how long a power station will run a fridge.