What size power station for a CPAP machine?

By the Ferncharge team · Figures last checked 18 October 2026

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Important: this page is about electricity, not treatment. It isn't medical advice. Before you rely on any battery or power station for a CPAP or other medical device, check with your equipment supplier or clinician. Ask them which power sources and accessories the device maker approves. Ferncharge has not tested any power station with any medical device.

The short answer: use the power figure in your own device's manual. As an example, ResMed states a typical power consumption of 56.1 W and a peak of 73.2 W for the AirSense 11 (ResMed AirSense 11 user guide). (We couldn't find these figures on ResMed's UK site. This is ResMed's Australia/New Zealand guide, and its Americas edition states the same.) Using our planning assumptions, a 1,000 Wh power station would supply that for roughly 11 hours at the peak figure, or about 14 hours at the typical figure, from its mains socket. That's an estimate, not a guarantee.

Compared on manufacturers' published specs. Ferncharge has not tested these products. Estimates only.

How much power does a CPAP use?

Only use figures from your device maker's own manual or spec sheet. They vary by model and accessories.

Your manual may list different figures depending on the accessories you use. If it isn't clear which figure applies to your set-up, ask your equipment supplier.

Estimating runtime

Runtime (hours) ≈ capacity (Wh) × 0.81 ÷ device watts, from the mains socket of a LiFePO4 power station (see methodology). For planning, we suggest using the peak figure, which gives the shorter, more cautious answer.

Rounded down. These are estimates from published figures, not measured runtimes. A cold or older battery delivers less.

Mains socket or DC?

ResMed lists an Air11 DC/DC converter among the AirSense 11's accessories (ResMed user guide). Using DC instead of the mains socket avoids inverter losses. Only use the power accessories your device maker approves, and check with your equipment supplier before changing how your device is powered.

What to look for in a power station

• Capacity (Wh) enough for the nights you need, using the peak figure and a margin. The sizing calculator adds a 20% margin.
• Continuous AC output comfortably above the device's power supply rating.
• Stated pure sine wave AC output, if your device maker's guidance mentions it.
• A stated UPS or switchover function if you want the power station to take over automatically in a power cut. Makers describe limits: Jackery's manual says its UPS "is a non-professional UPS function, it does not support 0ms switching. Do not connect to equipment with high uninterruptible power requirements", and asks you to "test several times to confirm compatibility before use" (Jackery manual). Ask your equipment supplier whether a UPS function is suitable for your device.

See stated specs side by side in the spec table. Example models (alphabetical): Anker SOLIX C1000 · BLUETTI AC180 · EcoFlow RIVER 3 · Jackery Explorer 1000 v2. Each name links to the maker's UK product page, where you can check the current price. Listing a model here doesn't mean it is approved for any medical device.

Power cuts: register and plan

• Priority Services Register: if you use medical equipment that needs a power supply, you can ask your energy supplier and network operator to add you (Ofgem). In power cuts, network operators must offer PSR customers extra help, for example battery packs for charging phones or medical equipment (Ofgem). In Northern Ireland, these registers are called Customer Care Registers (GOV.UK Prepare). NIE Networks, the network operator there, runs one for people who rely on electricity for healthcare needs (NIE Networks).
• Plan with your care provider: the government's Prepare campaign advises people who use medical equipment to plan for power cuts with their care provider (GOV.UK Prepare).
• Report a power cut: call 105 for free in England, Wales and Scotland, or 03457 643643 in Northern Ireland (GOV.UK Prepare).

Camping and travel

• Check with your equipment supplier before relying on a power station or battery away from home. ResMed's guide says to make sure you have "the appropriate power cord for the region you are traveling to", and to contact your care provider about buying one (ResMed AirSense 11 user guide). For planning, use your device's peak figure and the number of nights.
• Flying: the CAA doesn't allow lithium batteries over 160 Wh in passenger baggage, and 100–160 Wh needs airline approval (CAA). All four example power stations on this site exceed 160 Wh. Ask your airline and your device maker about approved travel batteries.

Safety

Follow your power station's manual and our safety guide: charge it on a hard, flat surface and away from escape routes.

FAQs

How many watts does a CPAP use?

It depends on the model and accessories. Use the figure in your manual. ResMed states typical 56.1 W and peak 73.2 W for the AirSense 11.

What size power station do I need for one night?

For an 8-hour night at ResMed's stated AirSense 11 peak (73.2 W), our planning formula gives about 723 Wh of rated capacity before any margin. Using the typical figure, it's about 554 Wh. Check with your equipment supplier before relying on it.

Can I use a power station for CPAP when camping?

We can only estimate the energy. Whether a particular power source is suitable for your device is a question for your equipment supplier or device maker.

Is a power station a medical backup?

No. Don't rely on our estimates for medical equipment. Speak to your equipment supplier or clinician, and join the Priority Services Register (in Northern Ireland, a Customer Care Register).

Related: Power cuts · Runtime calculator · Safety