How many nights can a power station run my CPAP?
Scenarios Updated 2026-08-01
Between roughly one night and five on the same battery, and the variable is the humidifier rather than the machine. The manufacturer’s own power-consumption table gives three figures for one popular unit: blower only, blower with humidifier, and blower with humidifier and heated tube — and the third is several times the first.
So the question "how many nights" cannot be answered by battery size alone. Turn humidification off and a small machine covers multiple nights; leave it and the heated tube on and the same battery covers one.
This page states electrical facts only — measured draw, waveform requirements and computed runtimes. It is not medical advice and makes no claim about whether any setup is suitable for therapy. For questions about your device, your therapy or travelling with either, ask the device manufacturer and your clinician.
One machine, three nightly figures
Energy per night, by configuration
All three come from one manufacturer power-consumption table for one device family, measured with a stated patient simulation and a named power meter. They are not a category estimate.
Humidification off. The cheapest way to buy nights, and it costs nothing but comfort.
See the record →The default configuration most people actually sleep with.
The most demanding common setup. The manufacturer sizes its own battery recommendations from a figure like this, with a safety margin on top.
The manufacturer’s own sizing basis for a night.
officialverified 2026-08-01CPAP machine record
What that is on two real machines
Worked runtimes
Computed by the same engine the calculator runs, in the humidifier-on configuration, including each station’s own idle consumption.
Usable energy 829.4 Wh divided by 22 W of machine plus 10 W.
See the pairing →Continuous hours divided by the 8 h session length the manufacturer sizes against. Switch the station off between sessions or its idle draw takes some of this back.
Usable energy 246.2 Wh divided by 22 W of machine plus 9.0 W.
See the pairing →Same division.
officialverified 2026-08-01engine · live run
The one waveform requirement we can cite
ResMed states in its own battery-power guide that its devices require a pure sine wave inverter, and recommends an inverter rated for far more continuous power than the machine actually draws. The same document carries a warning that its heated humidifiers, outside a short listed exception, must not be used with inverters at all. That is a manufacturer instruction with a document behind it, and it is the reason a waveform check appears in our verdict for this load. Another manufacturer’s battery-powered devices disable humidification automatically and say so in the manual. Read your own device’s documentation: these instructions differ by brand and by model, and none of them can be inferred from the electrical figures.
What the device maker asks for
The manufacturer’s inverter recommendation, alongside what the machine measurably draws. The gap between them is deliberate headroom on their part, not a contradiction.
The manufacturer’s own guidance for choosing an inverter.
A sizing recommendation for the inverter — not a measured inrush for the device.
What the device actually pulls, humidifier on, from the same manufacturer’s measurement table.
Low, which is why an inverter has to be sized on volt-amperes rather than watts for this load — the two are not the same number here.
officialverified 2026-08-01CPAP machine record · manufacturer guidance
Planning for more than one night
Two things make a multi-night plan behave worse than the arithmetic suggests, and both are avoidable. The first is leaving the station switched on all day between sessions: its own idle consumption is a continuous load, and over three days of daylight it can cost more than a night of therapy. Switch the machine off in the morning if it is not doing anything else. The second is the inverter itself. Running a small load through a mains inverter is the least efficient thing a power station does — the conversion loss is roughly fixed while the load is tiny, so a low-wattage device pays a disproportionate share of it. Feeding the device from a direct-current output instead removes that loss entirely, and it is also the route the device makers recommend first.
If the trip is longer than the battery, the answer is a recharge plan rather than a bigger battery. A modest panel replaces a night of the humidifier-on figure in a few good hours, which is a far lighter thing to carry than the equivalent extra capacity. The solar calculator will tell you whether your panel and your machine can actually do that together, because the answer depends on the voltage window as much as on the wattage.