Last summer, a mate headed off for three weeks in his campervan in southern Spain. Everything sorted: the itinerary, the surf spot, the cold beers. Except one detail. His CPAP. He has been using a ResMed AirSense for two years to treat sleep apnoea. Without it, he snores like a tractor, wakes every hour, and spends the day as a zombie. First night in the van, he plugs the CPAP into a cheap 50-pound inverter bought in a panic. Result: the machine throws an error, refuses to start, and he has the worst night of his trip. The problem? The inverter was outputting a modified sine wave. His CPAP demands a pure sine wave. Three weeks of misery could have been avoided with the right portable power station.
If you are amongst the roughly 1.5 million people in the UK who sleep with a CPAP, this guide is for you. Whether it is a road trip, camping, vanlife, or simply protecting against power cuts, here is exactly what you need.
Before talking stations, let us set out the numbers. Because CPAP consumption varies enormously depending on how you use it.
A CPAP without a humidifier draws between 30 W and 60 W depending on model and pressure setting. That is modest. Over an 8-hour night, that gives 240-480 Wh. Perfectly manageable for a mid-sized portable station.
Now switch on the heated humidifier -- and the numbers take off. Consumption climbs to 50-100 W. Over 8 hours: 400-800 Wh. Nearly double.
This is THE factor that changes everything in station sizing. The heated humidifier uses a resistive element to warm water and humidify the air you breathe. Maximum comfort, maximum greed.
My advice: if you are travelling with a portable station, switch off the heated humidifier or turn it to minimum. You easily gain 1-2 extra nights of autonomy. The air will be a touch drier, but you will still sleep.
Many recent CPAP machines (ResMed AirSense 11, Philips DreamStation 2) also offer a direct DC input at 12 V or 24 V. If your station has a compatible DC output, you eliminate the DC-to-AC-to-DC conversion losses and gain another 15-20% of autonomy. A dedicated DC cable costs 20-40 pounds -- it is the best investment you can make.
Here is the simplified calculation, with a 20% safety margin (because a battery never truly discharges to 0% in the real world).
Take a ResMed AirSense 10 set to 12 cmH2O pressure, no humidifier. Measured consumption: roughly 45 W.
Over 8 hours: 45 x 8 = 360 Wh. With the 20% margin: 360 x 1.2 = 432 Wh.
A 500 Wh station gives one full night with headroom. Two nights? Just about, if you are frugal -- but I would recommend 1000 Wh to be comfortable.
You can run this calculation yourself with our autonomy calculator.
This is the most critical point, and the one many people overlook. A CPAP is a sensitive medical device. It needs clean, regular current identical to your wall socket.
A CPAP uses an electronically controlled brushless motor. This motor adjusts its speed continuously to maintain the prescribed pressure in your airways. A modified (stepped) sine wave creates micro-voltage variations that can make the motor vibrate and generate noise, trigger errors and stop the machine, damage electronics over time, and distort pressure settings (dangerous for your health).
ResMed and Philips state clearly in their manuals: pure sine wave is mandatory if you power the machine via AC.
Cheap car inverters at 30-50 pounds are almost all modified sine wave. Even if the box says "sine wave", check it actually reads "pure" and not "modified" or "simulated." They are not the same thing.
The good news: all serious portable stations sold today (EcoFlow, Jackery, Bluetti, Anker, Goal Zero) deliver a pure sine wave on their AC outlets. It has become the standard. If you buy a recognised brand, you do not need to worry.
Classified by use and budget. All deliver pure sine wave and have sufficient AC output for a CPAP.
A station around 500 Wh. Autonomy: roughly 1 night without humidifier. The minimum viable option for power-cut backup or a single camping night.
700-800 Wh stations (EcoFlow RIVER 2 Pro, Bluetti EB70S). 1-2 nights without humidifier, roughly 1 night with low humidifier. Fast mains recharge (1-2 hours) rescues you if you find a socket during the day.
1000-2000 Wh stations (EcoFlow DELTA 2, Jackery Explorer 1000 Plus, Bluetti AC200L). 2-5 nights without humidifier, 1-2 with. Models with UPS and automatic switchover are ideal as home backup: during a power cut, the station takes over in under 20 ms without the CPAP stopping.
3000+ Wh stations (EcoFlow DELTA Pro, Bluetti AC300 + B300). 7+ nights without humidifier. Expandable. Honestly overkill for CPAP alone, but if the station also runs a fridge, lights, and chargers, it makes sense. Especially for home backup against power cuts.
Good news: CPAPs are classed as medical equipment by all major airlines. Your machine does not count towards cabin baggage allowance.
For the portable station, things differ. Lithium batteries are regulated on aircraft: under 100 Wh accepted in cabin without restriction (but 100 Wh is far too small for CPAP); 100-160 Wh accepted with airline approval; over 160 Wh prohibited in cabin AND hold.
So virtually every station capable of powering a CPAP for a full night (500 Wh+) is banned from aircraft.
The solution? Use a dedicated CPAP battery from the manufacturer (like the ResMed RPS II) or a specifically aviation-certified battery (like the Medistrom Pilot-24 for ResMed). These stay under 160 Wh and are designed to power the CPAP in DC mode, without humidifier, for one night.
The station-plus-solar-panel duo is total freedom. During the day, your 100-200 W panel recharges the station. At night, it powers the CPAP. With a 200 W panel and 5-6 hours of decent sun, you recover 600-900 Wh -- more than enough for one night without humidifier. Self-sufficient indefinitely, as long as the sun shines.
The station connects to the vehicle auxiliary battery or roof solar panel and recharges whilst you drive. In the evening, plug in the CPAP.
Some stations like the EcoFlow DELTA 2 or Bluetti AC200L offer pass-through mode: recharging and powering devices simultaneously. Connect the station to the van 12 V circuit, plug the CPAP into the station AC socket. Zero fuss.
Watch ventilation in vans -- restricted space means heat builds up. Place the station where air circulates.
This may be the most critical use. When power drops at 3 am and your CPAP switches off, you are left without treatment. For someone with severe apnoea (AHI above 30), that is potentially dangerous -- breathing pauses resume immediately.
A station with UPS function resolves this. Plug the CPAP into the station, the station into the mains. Normal operation: mains power passes straight to the CPAP. If the mains drops, the station switches to battery in under 20 ms -- so fast the CPAP does not even notice.
With a 1000 Wh station and a CPAP at 45 W without humidifier, you last over 18 hours. Even the longest power cut should not pose a problem.
Switch off the heated humidifier. The number-one battery saver. 30-50% less consumption.
Use the DC cable. Eliminates double conversion (battery DC to AC to CPAP DC). 15-20% more autonomy.
Pre-heat the humidifier on mains. If you must have the humidifier, run the CPAP on mains for the first 30 minutes to warm the water, then switch to the station. Residual heat gives 1-2 hours of "free" humidification.
Charge the station to 100% before bed. Obvious, but I see too many people head to a campsite with the station at 60%.
With a CPAP at medium pressure (10-12 cmH2O), no humidifier: consumption roughly 40-50 W. Over 8 hours: 320-400 Wh. With a 500 Wh station (real capacity around 450 Wh after losses): one full night, possibly two if your machine is economical. With the humidifier on full: one night will be tight. Move to 1000 Wh.
Yes, in the vast majority of cases. ResMed AirSense 10, AirSense 11, AirMini, and Philips DreamStation 1, DreamStation 2, System One all run on 230 V 50 Hz pure sine wave AC. Check two things: voltage (stations sold in Europe output 220-240 V) and the DC connector if you want to use DC output (manufacturer or third-party cables available for 20-35 pounds).
The ResMed AirMini is particularly interesting: ultra compact and designed for travel, it draws only 20-30 W. A 300 Wh station easily gives you 2 nights.
Most recent stations are near-silent under light load. A CPAP draws 30-60 W -- a light load for any 500+ Wh station. The internal fan often does not even trigger. Expect under 30 dB -- well below the CPAP itself (typically 26-30 dB).
Small caveat: some stations emit a very faint inverter whine at idle. If you are an ultra-light sleeper, test at home before travelling.
As detailed above, it is complicated. Lithium batteries over 160 Wh are banned on aircraft (cabin and hold). The smallest station capable of powering a CPAP for a night is at least 300 Wh. Alternatives: a dedicated CPAP battery from the manufacturer (under 160 Wh, aviation-certified) or plan for a station at your destination.
Depends on your use. Home backup: no, the station recharges on mains between outages. Camping/van/road trip: yes, strongly recommended. A 100-200 W panel makes you self-sufficient indefinitely. For camping beyond 2-3 nights, it is near-essential.
Cedric
You are in the middle of work. The fridge hums, the broadband router blinks, your PC is running. And suddenly, everything goes dark. Power cut. By the time you find a torch, plug the portable station into the fridge, and reboot the router, you have lost fifteen minutes and the thread of your Zoom me
*Last updated: March 2026*
March 2025. A colleague proudly shows me his Amazon find: a "3000 W" portable power station bought for 149 pounds. Gleaming black case, blue LCD screen, vaguely Asian gold logo. The product listing makes staggering promises: 3000 Wh capacity, "ultra-fast" solar recharge, compatible with "all devices
