Guide
CPAP during a power outage
Turn the humidifier and heated tube off during an outage if your doctor agrees. On ResMed's figures that cuts nightly use from about 440 Wh to about 56 Wh.
Medical safety notice: Will It Run? gives general power estimates only, not medical advice. Power draw varies by model, settings, pressure, humidifier and altitude. Before relying on any battery, power station, inverter or generator for a medical device, confirm approved power sources with the device manufacturer and your doctor or equipment supplier, and test your setup before an emergency. Never change prescribed settings to extend battery life. If your therapy is life-sustaining, keep the backup your supplier provides, register with your utility's medical-needs program, and have an evacuation plan. Run generators outdoors only, at least 20 ft from windows and doors, because of carbon monoxide risk. In an emergency, call 911.
Plan it before the storm
- Find your exact machine and setting below and note the watt-hours per night.
- If it will run on AC, add about 15 W for the station's inverter, multiply by 8 hours and the nights you want to cover, then divide by 0.85 to get the station size. On DC, skip the 15 W.
- Charge the station and test a full night on it before you need it.
- Ask your supplier whether your machine has a DC cord, which can stretch runtime.
- A generator can recharge the station, but only run it outdoors, far from windows and doors.
| Machine and setting | Average draw | 8-hour night | Nights on a 1,024 Wh station, AC | On DC, best case | Source |
|---|---|---|---|---|---|
| ResMed AirMini travel CPAP | 6.3 W | 50 Wh | 5.1 | 17.3 | ResMed |
| ResMed AirSense 11 AutoSet, no humidifier | 7 W | 56 Wh | 4.9 | 15.5 | ResMed |
| ResMed AirSense 10 AutoSet, no humidifier | 7 W | 56 Wh | 4.9 | 15.5 | ResMed |
| ResMed AirSense 11 with HumidAir 11 humidifier, no heated tube | 19 W | 152 Wh | 3.2 | 5.7 | ResMed |
| ResMed AirSense 10 AutoSet with HumidAir humidifier | 22 W | 176 Wh | 2.9 | — | ResMed |
| ResMed AirSense 10 with HumidAir and ClimateLineAir heated tube | 34 W | 272 Wh | 2.2 | — | ResMed |
| ResMed AirSense 11 with HumidAir 11 and ClimateLineAir 11 | 55 W | 440 Wh | 1.6 | 2.0 | ResMed |
| ResMed AirSense 11, typical power from the user guide | 56.1 W | 449 Wh | 1.5 | 1.9 | ResMed |
| Philips DreamStation, worst case at the 80 W power supply rating | 80 W | 640 Wh | 1.1 | — | Philips |
AC nights = 1,024 Wh × 0.85 usable ÷ ((watts + about 15 W inverter draw) × 8 hr). DC nights = 1,024 Wh × 0.85 ÷ (watts × 8 hr), a best case with the maker's DC converter (ResMed Air11, Air10 or AirMini) in a 12 V car port; — means DC isn't modeled for that setting (ResMed's AirSense 10 guide says humidity off on an external battery, and Philips publishes no DC figure). ResMed figures are lab measurements from ResMed's published power table; the Philips row is the 80 W power-supply ceiling, a worst case. The 15 W is the inverter's own draw: BLUETTI counts about 15 W of self-consumption in its AC180 runtime formula, and an owner test measured about 17.5 W on a DELTA 3 Plus; larger stations can idle higher. Method, DC converter limits and picks: CPAP power station guide. The RIVER 2, RIVER 3 Plus and SOLIX C300 DC figures use their 12 V car outputs (EcoFlow RIVER 2 manual: 100 W max; RIVER 3 Plus specs: 126 W max; Anker C300 guide: 12 V 10 A). The DELTA Pro 3 has 12 V Anderson and DC5521 outputs but no car socket, so it stays AC-only here.
Nights on each station
Anker SOLIX F3800 row: nights use about 40 W of idle draw instead of 15 W, because Anker's FAQ for the F3800 Plus lists about 40 W with AC on and nothing connected (Anker). At CPAP loads that cuts its nights by roughly a third to a half; see the F3800 idle table. The F3800 DC column uses its 12 V ⎓ 10 A car charger output (Anker US user guide), which skips the inverter.
Nights of 8 hours. AC = nameplate Wh × 0.85 ÷ (average draw + about 15 W inverter draw). DC = nameplate Wh × 0.85 ÷ average draw, a best case with ResMed's Air11 DC converter in the 12 V car port; — means no car port is listed in the maker specs we checked. As an Amazon Associate we earn from qualifying purchases. The 15 W is the inverter's own draw: BLUETTI counts about 15 W of self-consumption in its AC180 runtime formula, and an owner test measured about 17.5 W on a DELTA 3 Plus; larger stations can idle higher. Method, DC converter limits and picks: CPAP power station guide.
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Questions
How do I power a CPAP during a power outage?
Use a portable power station sized for your nightly watt-hours, or your machine's DC cord with a suitable battery. Confirm approved sources with your supplier.
What happens to a CPAP when the power goes out?
It stops delivering pressure unless it is on a battery or power station. Keep your mask on only if the machine is running.