How long will a power station run a CPAP machine?

Every power station we compare

Running a CPAP machine on its own from the AC outlet, smallest first.

Runtime: capacity × 90% usable × 85% inverter efficiency ÷ (the appliance's average draw + about 10W the station uses itself), a range from the low and high average draw. "Runs it?" checks the station's output against 4–20W running, the cautious figures from generator makers' and DTE Energy's charts. Many modern appliances start with less, so "Check" means read your appliance's label (amps × 120 = watts). Plan on the low end of every runtime.

Where the figures come from

CPAP (blower only: humidifier and heated tube off). ResMed’s own battery guide lists the current each machine draws at 12V DC for each treatment pressure. Converted to watts, the AirMini draws 4.4–9.1W at 6–20 cmH2O, and the AirSense 10 with SlimLine tubing and no humidifier 8.4–19.9W. Higher pressure means more watts, so ask your sleep service for your set pressure rather than guessing. Philips’ DreamStation 2 manual gives only an 80W power supply and its input current rating, not running watts. ResMed recommends its DC-to-DC converter over an inverter. Running from a power station’s 12V outlet through the maker’s converter avoids inverter losses. Where an inverter is used, ResMed recommends a pure sine wave one. A 5–20W load is small enough that a power station’s auto-off can cut it in the night; BLUETTI says to disable ECO mode for devices under 60W. No start-up surge is published. Always follow the device maker and your sleep service, and see medical devices in a power outage.

CPAP with heated humidifier (and heated tube). ResMed’s battery guide covers the AirSense 10 at 12V DC through ResMed’s converter. With the humidifier at setting 4, the whole machine draws 20.8–50.3W across 6–20 cmH2O. With the humidifier at 8 it draws 41.3–55.1W, and with the humidifier at 8 plus ClimateLineAir heated tubing at 86°F, 56.5–67.3W. Philips does not publish per-mode figures for the DreamStation 2. The humidifier and heated tube are the big loads, so in a long outage ask your sleep service whether you can run with humidification off, which brings the draw down to the blower-only range. ResMed’s guide warns that some older ResMed heated humidifiers, including the original HumidAire, must not be used with inverters, so check your own model’s guide. Treat pure sine as the minimum for any CPAP on an inverter. The heaters cycle rather than surge, so averageW mirrors running watts. See medical devices in a power outage.

Questions

Other appliances

Power stations compared →