Guide
How many watts does a CPAP use?
ResMed measures its CPAPs at 6.3 to 7 W without a humidifier, 19 to 22 W with a humidifier, and 34 to 55 W with a heated tube.
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.
| 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 power supply rating on the brick (65 W, 80 W or 90 W) is a maximum, not the typical draw. ResMed's AirSense 11 user guide lists a 56.1 W typical and 73.2 W peak system figure, which Willrun uses as its default AirSense 11 row. To measure your own machine, a plug-in watt meter gives the real number at your settings.
BiPAP
| Machine and setting | Average draw | 8-hour night | Nights on a 1,024 Wh station, AC | On DC, best case | Source |
|---|---|---|---|---|---|
| ResMed AirCurve 11 VAuto BiPAP, no humidifier | 8 W | 64 Wh | 4.7 | 13.6 | ResMed |
| ResMed AirCurve 10 VAuto BiPAP, no humidifier | 9 W | 72 Wh | 4.5 | 12.1 | ResMed |
| ResMed AirCurve 10 VAuto BiPAP with HumidAir humidifier | 23 W | 184 Wh | 2.9 | — | ResMed |
| ResMed AirCurve 11 VAuto BiPAP with HumidAir humidifier | 34 W | 272 Wh | 2.2 | 3.2 | ResMed |
| ResMed AirCurve 10 VAuto BiPAP with HumidAir and heated tube | 41 W | 328 Wh | 1.9 | — | ResMed |
| ResMed AirCurve 11 VAuto BiPAP with HumidAir and heated tube | 66 W | 528 Wh | 1.3 | 1.6 | ResMed |
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.
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Questions
How many watts does a CPAP use?
ResMed measures its CPAPs at 6.3 to 7 W without a humidifier, 19 to 22 W with a humidifier, and 34 to 55 W with a heated tube.
Is the power supply rating the real draw?
No. It is the maximum the supply can deliver. Typical draw is lower.