Running a CPAP machine off a battery while camping

Look up your own machine's power number first. As one example, the ResMed AirSense 11 comes with a 65 W power supply, and that is a ceiling, not what it normally draws.

This page is about electricity only. It isn't medical advice. Ask your doctor or your machine's maker about powering the device away from home.

What we found for the ResMed AirSense 11

• The supply in the box is rated 65 W, with a 24 V output at 2.71 A. (Easy Breathe, The CPAP Shop)
• A heated humidifier and heated tube pull more power than the machine alone. Neither retailer gives a wattage. (The CPAP Shop)
• The CPAP Shop says a converter made for this machine makes a battery last nearly twice as long as running it through a household-power inverter, and that heating on an inverter costs 30 to 40% of battery life. That is a retailer's claim and we haven't tested it.

retailers only Both sources are shops. We haven't found ResMed's own number for typical use.

What that means for a battery

At the 65 W ceiling, a night of 8 hours is at most 520 Wh. With 15% lost in conversion, about 612 Wh. That's our arithmetic, and it's a worst case. Your machine may draw much less.

Use the sizing tool with the number from your own manual.

What we haven't found

• ResMed's published power figures, with and without the humidifier.
• The same numbers for other makers' machines.