A CPAP is the one appliance where "roughly enough" isn't good enough. You need a number you can rely on for a specific machine, on a specific night, and most manufacturer runtime tables don't list CPAPs at all.
What a CPAP actually draws
A CPAP without humidification typically draws 30 to 60W, depending on your pressure setting and mask leak. That's a modest load, and almost any power station will run one. The variable that wrecks people's calculations is the heated humidifier, which can double or triple total consumption because it's a heating element rather than a motor.
The heated hose is a second, smaller offender. Between them, a machine that sips 35W with everything off can pull well over 100W with full humidification and a heated tube in a cold bedroom.
The single most useful change you can make: turn off the heated humidifier when running from battery. It routinely doubles your nights per charge, and most users find a nasal saline spray an acceptable substitute for one or two nights.
Nights per charge, by capacity
| Station | Capacity | No humidifier (~40W) | With humidifier (~100W) |
|---|---|---|---|
| Elite 30 V2 | 288Wh | ~6 hrs — one night | ~2.5 hrs — not viable |
| AC70 | 768Wh | ~16 hrs — two nights | ~6.5 hrs — one night |
| Elite 100 V2 | 1,024Wh | ~21 hrs — three nights | ~8.5 hrs — one night |
| AC180 | 1,152Wh | ~24 hrs — three nights | ~9.5 hrs — one night |
| Elite 200 V2 | 2,073Wh | ~43 hrs — five nights | ~17 hrs — two nights |
These are calculated from published capacity with realistic conversion losses, not measured on a specific machine. Treat them as a planning range and test your own setup before you depend on it.
Use the DC output if your machine supports it
Many CPAPs accept 12V DC directly, usually via an optional cable from the manufacturer. Running from a station's 12V DC port instead of an AC outlet skips the inverter entirely, and that typically saves 10 to 15% of your total consumption. Over a week of camping that's most of an extra night.
It also means the inverter can stay off, which cuts the station's own idle draw substantially — on some models from around 12W to under 5W. On a small battery running a small load, the station's own consumption is a meaningful share of the total.
The UPS question
If the reason you want a battery is grid outages rather than camping, switching speed matters more than capacity. A unit with UPS pass-through sits between the wall and the machine, so a power cut doesn't wake you. Anything at 10ms or faster is comfortably quick for a CPAP.
Usefully, this doesn't require a large purchase. The smallest unit in the range switches in 10ms, which is faster than several models costing three times as much. We cover the tiers in detail in our guide to UPS switching speed.
The sensible CPAP pick
1,024Wh covers roughly three humidifier-free nights, and 10ms UPS switching means a grid cut won’t wake you.
Flying with it
You can't. Airlines cap lithium batteries in carry-on at 100Wh, with some allowing up to 160Wh by prior arrangement, and power stations are banned from checked baggage entirely. Even the smallest unit here is 288Wh — nearly three times the limit. For air travel you need a dedicated CPAP battery sold specifically as flight-legal, or arrangements at your destination.
Practical checklist
- Measure your machine first. A plug-in energy meter over one night gives you a real Wh figure, which beats every estimate on this page.
- Decide about the humidifier before you size the battery. It's the difference between 288Wh being plenty and being useless.
- Ask your supplier about a 12V DC cable. The efficiency gain is free once you own it.
- If it's for outages, check switching speed, not just capacity.
- Test a full night at home before relying on it somewhere remote.
Keep reading
RV power stations: the ports that matter
TT-30, 12V DC, alternator charging — and the honest answer on air conditioning.
Cold weather: four things to know first
Never charge below freezing. Plus capacity loss, panel voltage and heating loads.
What "expandable" really means
True expansion vs Power Bank Mode. Neither raises your output ceiling.
This article is general guidance on powering equipment, not medical advice. CPAP power consumption varies substantially between machines, pressure settings and mask types — consult your device manual and your equipment supplier, and test your own setup before depending on it away from mains power.