How many nights will your CPAP run?
Compare the AC outlet with a DC converter, with and without the humidifier.
- CPAP energy per night
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- Via the AC outlet
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- Via a DC converter
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Energy planning only, not medical advice. Agree an outage plan with your clinician and equipment supplier, and test a full night before you rely on it.
The humidifier and the inverter decide most of it.
ResMed's battery guide sizes an AirSense 10 at 10 cmH₂O for an 8-hour night at about 7Ah on a 12V battery without humidification and about 28Ah with the humidifier at setting 4, and notes that an inverter setup needs roughly two to three times the capacity of a DC converter setup. This calculator shows the same effect with your numbers. The 8W idle draw is a planning default; many stations use more with the AC output on, which pushes the AC route toward ResMed's two-to-three-times figure. Raise it if you have measured your station. Read the full CPAP backup power guide.
Frequently asked questions
How many nights can a 1,000Wh power station run a CPAP?
It depends mostly on the humidifier and the power path. At about 10.5W without humidifier for 8 hours, a 1,024Wh station with a 20% reserve covers several nights on either path in this model; at about 42W with the humidifier, it covers far fewer.
Is DC better than AC for a CPAP on a power station?
Usually yes. A manufacturer-approved DC converter avoids converting battery DC to AC and back, and avoids the inverter's own idle draw, which matters a lot for a small load like a CPAP.
Where do the preset values come from?
From ResMed's battery guide for the AirSense 10 at 10 cmH₂O: about 7Ah (roughly 84Wh) per 8-hour night without humidification and about 28Ah (roughly 336Wh) with the humidifier at setting 4, converted to average watts. Your machine and settings will differ.