Portable Power Station for CPAP: How to Size One
How to check your CPAP's power draw, work out how many nights a power station covers, and where to look if you want to buy one.
Last updated September 2026
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This is general power information, not medical advice. If you depend on a CPAP, talk with your equipment supplier or doctor about a backup power plan. Check compatibility with your CPAP's maker before you buy anything. This guide is part of our backup power section.
Sizing a power station for a CPAP starts with one number: your machine's real wattage. Find it on its label or in its manual. From there, the math has three steps. Find your watts, multiply by hours, then add margin for inverter loss.
A portable power station for CPAP use should be tested before it becomes part of a medical backup plan. Confirm the plug, output type and settings used each night. Size from the exact machine's draw, add margin above the calculated need, and use only accessories the CPAP maker confirms for that model. Capacity alone does not prove compatibility.
A worked example using one named model's real numbers
ResMed publishes power-draw figures for its AirSense 10 machine. It's 7W running with no humidifier. Add the humidifier and it rises to 22W. Add a heated tube too and it's 34W.
These are one model's own numbers, not a stand-in for every CPAP. Your own machine may draw more or less, so check its label first.
Take the 7W running-only figure over an 8-hour night. That's 7W x 8h = 56Wh before the station's own use and conversion loss. The real need will be higher, so do not size the battery to exactly 56Wh.
Now take the 34W heated-tube figure over the same 8 hours. That's 34W x 8h = 272Wh before conversion loss. A 286Wh station, like the RIVER 3 Plus in our best portable power stations guide, leaves almost no rated margin at all. A 1,024Wh unit, like the Elite 100 V2 in our best solar generators for home backup roundup, starts with much more room for that load.
The middle ResMed figure is useful too. At 22W for 8 hours, the machine uses 176Wh before conversion loss. That fits below a 286Wh rating on paper, but the paper gap is not a guarantee. Test the exact machine, humidifier setting, hose and power path together.
Factors to consider when sizing a power station for CPAP use
Find your CPAP's real wattage first. It's on the device label or in the manual, usually as a range based on pressure setting and humidifier or heated-tube use. Don't guess from a different model, and don't assume the AirSense 10 figures above apply to your machine.
Add margin. Don't cut it close. Inverters lose some power to heat, and a battery rarely gives its full rated capacity in real use. Buy more than your bare-minimum math says, especially if the outage could run longer than one night.
Check pure sine wave output and DC options. Confirm your CPAP's power requirement against the unit's spec sheet. Ask the CPAP maker directly if the manual doesn't say. Some CPAP makers sell DC cords or converters for specific machines. Use one only when the maker confirms it is compatible with your exact model.
Plan for a recharge if the outage runs long. A solar input rating, covered in our best solar generators for home backup guide, matters more the longer an outage might run.
Keep a written note of your machine's settings. Pressure setting, humidifier level and tube type all change the real wattage draw. If you switch power stations or travel with a spare, having those settings written down means you don't have to recalculate from memory during an actual outage.
Test the full CPAP backup setup
Do a trial while grid power is available. Use the same mask, humidifier and heated tube that you expect to use in an outage. Connect through the same AC outlet or approved DC accessory. Confirm that the machine starts and stays on when the station is unplugged from the wall.
Write down the battery level before bed and after the test. That result applies to your setup in those conditions. It is more useful than a generic nights-per-charge claim. Repeat the check after a major settings change or after replacing the machine.
Keep the power cord, any approved DC adapter and the station charger together. If solar is part of the plan, test those cables too. A missing adapter can make a full battery useless to the CPAP it was meant to support.
Portable power station for CPAP verdict
Start with the draw published for your exact CPAP, not a broad estimate. Multiply watts by the hours you sleep, then choose a station with room above that result. The AirSense 10 example ranges from 56Wh to 272Wh over 8 hours before conversion loss, based on which comfort features are active.
Test the whole setup before an outage. If you rely on CPAP therapy, review the backup plan with your equipment supplier or doctor as well as the power-station maker.
Questions people also ask
How much power does a CPAP use overnight?
It varies a lot by model and by whether the humidifier or heated tube is running. ResMed's own published figures for its AirSense 10 list 7W running with no humidifier, rising to 22W with the humidifier and 34W with a heated tube. That's one named model's numbers, not a figure for every CPAP; check your own machine's label.
Does my CPAP need a pure sine wave power source?
Check your CPAP's manual for its exact requirement. ResMed's own power documentation for the Air10/Lumis series covers battery compatibility. The safest approach is to confirm your exact model against the power station's spec sheet before an outage, not during one, and to call the CPAP maker if the manual doesn't say.
How many nights will a power station run my CPAP?
Divide the unit's Wh capacity by your CPAP's real overnight draw in watt-hours (wattage times hours used), then subtract a margin for inverter loss. A machine drawing 7W all night uses very little; one running a heated humidifier and tube at 34W uses much more. Work the math for your own capacity and wattage rather than assuming a fixed number of nights.
Is there a way to run a CPAP without losing power to an inverter?
Some CPAP makers sell a DC power cord or DC-to-DC converter for specific machines. Check your CPAP maker's accessories page or call them to confirm whether your exact model supports one. Use only the model-compatible accessory and connection method the maker specifies.