CPAP Power Guide (2026): Watts by Setting From ResMed's Tables
Table of Contents
Affiliate disclosure: Some links on this page are affiliate links, including links to Amazon, EcoFlow and BLUETTI. If you buy through them we may earn a commission, at no extra cost to you. As an Amazon Associate we earn from qualifying purchases. This never influences our rankings or verdicts.
How long will a solar generator run your CPAP?
On ResMed's own measurements, an AirSense 10 draws about 8 to 20W with its humidifier off, depending on pressure, so a 1,024Wh solar generator runs it for roughly 43 hours or more, about five nights. With the heated humidifier at its highest setting it draws about 41 to 55W, and about 57 to 67W with a heated tube as well, which cuts a 1,024Wh unit to about 13 to 16 hours. The humidifier decides how many nights you get.
Every draw in this CPAP power guide comes from the tables in ResMed's battery guide, which list the current each machine pulls from a 12V battery through ResMed's DC-to-DC converter at each pressure setting; we converted amps to watts (amps x 12V). For other machines, check the maker's manual or measure with a plug-in watt meter. For other appliances, see our solar generator runtime cheat sheet.
CPAP power guide: draw by model and setting
ResMed's guide dates from 2018, so it covers the AirSense 10, AirMini and S9 series but not the AirSense 11; we found no equivalent table from ResMed for the AirSense 11, so measure that one yourself. Ranges run from 6 to 20 cmH2O unless noted.
| Machine and setup | Draw (ResMed's figures) |
|---|---|
| AirSense 10, humidifier off | About 8-20W |
| AirSense 10, humidifier at 4 | About 21-50W |
| AirSense 10, humidifier at 8 (highest) | About 41-55W |
| AirSense 10, ClimateLineAir heated tube at 30°C and humidifier at 8 | About 57-67W |
| AirMini travel CPAP (waterless HumidX) | About 4-9W |
| S9 AutoSet or Elite, humidifier off | About 5-12W |
| S9 AutoSet or Elite, H5i humidifier at 6 | About 55-72W |
| S9 VPAP S or ST (bilevel), humidifier off, IPAP 10 to 25 cmH2O | About 6-19W |
| S9 VPAP S or ST, H5i humidifier at 6, IPAP 10 to 25 cmH2O | About 58-76W |
Two patterns stand out. The humidifier matters far more than pressure: on an AirSense 10, the humidifier at its highest setting adds about 33 to 35W at every pressure. And a bilevel (BiPAP) machine is not automatically a bigger load: ResMed's S9 VPAP draws about the same as its S9 CPAP at the same pressure, and more only because bilevel prescriptions often run higher.
Runtime table: CPAP hours by generator capacity
Runtime (hours) = capacity (Wh) x 0.85 / draw (W), using the top of each ResMed range. ResMed measured through its 12V DC converter, so these hours assume you run the machine from the power station's 12V outlet with that converter; through the AC outlet, expect less (see the next section).
| Machine and setup | 300Wh | 512Wh | 1,024Wh | 2,048Wh | 3,600Wh |
|---|---|---|---|---|---|
| AirSense 10, humidifier off (20W) | 12.8 hrs | 21.8 hrs | 43.5 hrs | 87 hrs | 153 hrs |
| AirSense 10, humidifier at 8 (55W) | 4.6 hrs | 7.9 hrs | 15.8 hrs | 31.7 hrs | 55.6 hrs |
| AirSense 10, heated tube and humidifier at 8 (67W) | 3.8 hrs | 6.5 hrs | 13 hrs | 26 hrs | 45.7 hrs |
| AirMini (9W) | 28.3 hrs | 48.4 hrs | 96.7 hrs | 193 hrs | 340 hrs |
| S9 VPAP bilevel, humidifier off, IPAP 25 (19W) | 13.4 hrs | 22.9 hrs | 45.8 hrs | 91.6 hrs | 161 hrs |
| S9 VPAP bilevel, H5i at 6, IPAP 25 (76W) | 3.4 hrs | 5.7 hrs | 11.5 hrs | 22.9 hrs | 40.3 hrs |
The DC advantage: what the inverter costs you
Most CPAP users plug into AC. From a solar generator, that means the battery's DC goes through the station's inverter to 120V AC, and then the CPAP's own power supply converts it back to DC. ResMed strongly recommends its DC-to-DC converters over any inverter, and its battery guide shows why: for the S9, the same machine at the same pressure drew about 40% to 130% more battery current through a 300W pure sine wave inverter than through ResMed's DC converter with the humidifier off, and about 7% to 20% more with the H5i humidifier at 6. The penalty is largest at small loads, which is exactly where a CPAP with its humidifier off sits.
EcoFlow's DELTA 3 has a 126W car port (12.6V) that works with CPAP DC cables. ResMed lists DC-to-DC converters for the AirMini, Air10 (AirSense 10) and S9 series in its battery guide, and sells an AirSense 11 DC/DC converter for 12V or 24V sources. Before buying, confirm with your CPAP maker that the cable or converter suits your machine, and check that the power station's 12V outlet can supply it.
The humidifier decision
The heated humidifier is the biggest power draw on a CPAP. On ResMed's AirSense 10 figures, at 10 cmH2O the machine goes from about 11W with the humidifier off to about 44W with it at its highest setting, four times the draw. If you're on battery power, it is the first thing to turn down or off.
Ways to manage humidifier draw:
- Turn the humidifier down: at 10 cmH2O, setting 4 draws about 28W against about 44W at setting 8.
- Skip the heated tube on battery: ClimateLineAir at 30°C adds roughly another 12 to 15W on top of the humidifier at 8.
- Use a HumidX: the AirMini humidifies with a waterless HumidX, so it stays at about 4 to 9W, the lightest load in ResMed's tables.
- Turn it off during long outages: many users can sleep without it for a few nights. Dry air can irritate the throat, and saline nasal spray can help; ask your doctor or equipment supplier if you're unsure.
Which solar generator should you buy for CPAP backup?
Our picks are based on published specifications, pricing, warranty terms and owner reports. Runtimes use ResMed's AirSense 10 figures.
1 night: The EcoFlow RIVER 2 Max (499Wh, about $309) covers a night with the humidifier off with plenty to spare (about 21 hours at 20W) and most of a night with it on high (about 7.7 hours at 55W). With the humidifier off, even a 243Wh RIVER 2 lasts about 10 hours. See our best solar generators for CPAP for more options.
EcoFlow RIVER 2 MaxBuy at EcoFlow
2 nights with the humidifier on: A 1,024Wh unit gives about 15.8 hours at 55W, or about 43.5 hours with the humidifier off. The EcoFlow DELTA 3 (about $629) has a 126W car port for DC CPAP cables and an under-10ms switchover, so a CPAP plugged into it keeps running when the grid drops. The BLUETTI Elite 100 V2 (about $499, 10ms switchover) is the lower-cost alternative. See the EcoFlow DELTA 3 review.
EcoFlow DELTA 3Buy at EcoFlowCheck price on Amazon
4 nights with the humidifier on: A 2,048Wh unit gives about 31.7 hours at 55W (2,048 x 0.85 / 55). The EcoFlow DELTA 3 Max (about $899) or the BLUETTI AC200PL (2,304Wh, about $950, the successor to the AC200L) fit here.
EcoFlow DELTA 3 MaxBuy at EcoFlowCheck price on Amazon
BLUETTI AC200PLCheck price on Amazon
Extended outages, or a bilevel machine with a heated humidifier: A 3,600Wh unit like the EcoFlow DELTA Pro (about $1,799) gives about 40 hours for an S9 VPAP at IPAP 25 with its H5i humidifier at 6 (3,600 x 0.85 / 76), about five nights.
EcoFlow DELTA ProBuy at EcoFlowCheck price on Amazon
Common mistakes when running a CPAP on battery
- Leaving the humidifier on full: on ResMed's AirSense 10 figures it cuts runtime by two thirds or more. This is the single most effective change you can make.
- Running through the inverter when a DC converter would do: ResMed's S9 tables show an inverter drawing about 7% to 130% more from the battery, the most with the humidifier off. Confirm DC compatibility before any camping or backup planning.
- Buying a unit that's too small: a 300Wh battery runs an AirSense 10 with its humidifier on high for about 4.6 hours, not a full night. Know your machine's actual draw before buying.
- Not testing before relying on it: test your full setup (generator, cable and CPAP) at home before you need it during an outage or on a camping trip. Some DC cable combinations have compatibility issues that appear only when the devices interact.
Frequently Asked Questions
How long will a solar generator run a ResMed AirSense 10?
On ResMed's figures, an AirSense 10 draws about 8 to 20W with its humidifier off, depending on pressure. On a 1,024Wh solar generator (at 0.85 efficiency) that's about 43.5 hours at 20W, five nights or more. With the humidifier at its highest setting (up to about 55W) it drops to about 15.8 hours, and with a heated tube as well (about 67W) to about 13 hours. Turning the humidifier down or off is the single most effective way to extend CPAP runtime on battery.
What is the best solar generator for CPAP use?
With the humidifier off, even a 300Wh unit covers a night on ResMed's AirSense 10 figures. With the humidifier on high, a 1,024Wh unit with a fast UPS switchover such as the EcoFlow DELTA 3 or BLUETTI Elite 100 V2 gives about two nights, and a 2,048Wh unit such as the EcoFlow DELTA 3 Max about four. For a bilevel machine with a heated humidifier, or long outages, the 3,600Wh EcoFlow DELTA Pro gives about 40 hours at 76W.
Does a CPAP need a pure sine wave inverter?
Use one if you use an inverter at all. ResMed recommends a pure sine wave inverter, and a DC-to-DC converter in preference to any inverter; its battery guide lists only a few older machines that can run from a modified sine wave inverter. Current power stations from EcoFlow, Jackery, BLUETTI and Anker SOLIX use pure sine wave inverters, so this is not an issue with any of them.
Can I run my CPAP from a car battery or 12V DC?
Yes, with the maker's DC cable or converter. ResMed lists DC-to-DC converters for its AirMini, AirSense 10 and S9 series in its battery guide and sells one for the AirSense 11, and EcoFlow's DELTA series provides a 12.6V car port. ResMed's S9 tables show its DC converter using about 7% to 56% less battery current than a 300W inverter, the biggest saving with the humidifier off. Confirm your model's DC compatibility before buying a cable.
How much power does a CPAP use per night?
On ResMed's AirSense 10 figures, an 8-hour night uses about 64 to 160Wh with the humidifier off (8 to 20W) and up to about 440Wh with the humidifier at its highest setting (55W), or about 540Wh with a heated tube as well (67W). The AirMini, at about 4 to 9W, uses about 35 to 73Wh a night, so a 300Wh unit runs it for several nights.
Will turning off the CPAP humidifier affect my therapy?
Turning off the humidifier reduces comfort but does not change the air pressure your machine delivers. Some users get a dry mouth, nasal dryness or mild throat irritation without humidification, and saline nasal spray before sleep can help. Many users manage a few nights without it, especially in humid weather; ask your doctor or equipment supplier if you're unsure.
How long will a solar generator run a BiPAP machine?
On ResMed's figures its S9 VPAP bilevel machines draw about 6 to 19W with the humidifier off (IPAP 10 to 25 cmH2O), about the same as its S9 CPAP at the same pressure, and about 58 to 76W with the H5i humidifier at 6. On a 1,024Wh solar generator that's about 45.8 hours at 19W or about 11.5 hours at 76W; a 2,048Wh unit gives about 23 hours with the humidifier on.
Is the ResMed AirMini good enough for home backup use?
Its draw makes it excellent for power backup: ResMed lists about 4 to 9W, about half of an AirSense 10 with its humidifier off at the same pressure. It uses a waterless HumidX instead of a heated water humidifier, and its hose is smaller. For occasional emergency backup it is a strong choice; for nightly home use, many people prefer a full-size machine with a heated water humidifier.
