How to choose a battery for the ResMed AirSense 11
Choosing the right battery for the ResMed AirSense 11 comes down to one number: how much power your machine actually draws. The AirSense 11 uses a 65-watt power supply, smaller than the AirSense 10's 90-watt brick. But the machine doesn't draw 65 watts continuously. Here's what it actually uses:
| Setting | Power draw | 8-hour runtime needs |
|---|---|---|
| CPAP only (no humidity, no heat) | 4-8W | 32-64 Wh |
| CPAP + humidifier (no heated tube) | 15-25W | 120-200 Wh |
| CPAP + humidifier + heated tube | 30-60W | 240-480 Wh |
| AutoSet (auto-adjusting pressure) | 5-10W base | Varies with events |
This matters because it determines which battery you need and how long it'll last. Turn off the humidifier and heated tube, and a small 100Wh battery runs the AirSense 11 for two full nights. Leave everything on, and you need a much bigger battery.
Three ways to power an AirSense 11 on battery
1. DC battery with direct cable (best efficiency)
A DC battery connects directly to the AirSense 11's power input, skipping the AC power brick entirely. This is the most efficient option — no energy lost converting DC to AC and back to DC.
The AirSense 11 uses a 20V DC input. You need a battery that outputs 20V and comes with the right cable (or you buy the cable separately). Going DC-direct typically recovers 10-15% of capacity that an inverter would otherwise waste — on a 100Wh battery that is roughly an extra 1.5-2 hours of CPAP-only runtime. Expect about 12-18 hours per 100Wh at a 6-8W CPAP-only draw. For the full sizing math, see our CPAP battery runtime calculator.
2. Portable power station with AC outlet
Any portable power station with a pure sine wave inverter works. Plug the AirSense 11's stock power brick into the AC outlet. Simple, but you lose 10-15% efficiency to the DC-AC-DC conversion, and the inverter itself adds 5-10W of idle overhead. A 256Wh station still delivers 3-4 nights of CPAP-only therapy or one full night with the heated humidifier running. For nightstand outage protection, choose a model with a UPS or passthrough mode so it switches over in milliseconds — see our breakdown of UPS vs CPAP battery vs power station.
3. Car battery with 12V inverter
For RV and car camping, a 12V-to-AC inverter rated at 150W+ will run the AirSense 11. Not ideal for efficiency, but it works when your car battery is the only power source. A CPAP-only night pulls roughly 60-90Wh from a 12V source, so a typical 50Ah deep-cycle battery handles several nights. A 12V-to-20V DC converter is more efficient than an inverter if you go this route. Running the heated humidifier off a vehicle battery is not recommended — see our CPAP humidifier battery drain guide for why heat is the single biggest drain.
Best batteries for the AirSense 11
For travel and flights
Why it works: The Medistrom Pilot-24 Lite was designed for CPAP machines. It connects to the AirSense 11 via a DC cable (included), outputs 20V, and is FAA-approved at 97.68Wh (under the 100Wh carry-on limit). You get 1-2 full nights without the humidifier.
Runtime estimate:
- Without humidifier: 12-24 hours (1-2 nights)
- With humidifier: 4-6 hours (not quite a full night)
Price: $169 – $199
For camping and extended trips
Why it works: The EcoFlow RIVER 2 has 256Wh of capacity — enough for 3-4 nights without the humidifier or one full night with everything on. It charges from solar panels, car outlet, or wall power. Pure sine wave inverter built in.
Runtime estimate:
- Without humidifier: 30-60 hours (3-7 nights)
- With humidifier + heat: 5-8 hours (1 night)
Price: $179 – $239
For power outages at home
Why it works: The Jackery Explorer 240 v2 sits on your nightstand and takes over when the power goes out. At 256Wh, it runs the AirSense 11 for 3+ nights without the humidifier. Supports passthrough charging, so it stays topped up while plugged into the wall and kicks in automatically during an outage.
Runtime estimate:
- Without humidifier: 30-60 hours (3-7 nights)
- With humidifier + heat: 5-8 hours (1 night)
Price: $129 – $209
Budget option
The Freedom V² CPAP Battery is purpose-built for CPAP machines. It's smaller than the options above (40-50Wh depending on model) but connects via DC for maximum efficiency. Gets you through one night without the humidifier.
Runtime estimate:
- Without humidifier: 6-12 hours (1 night)
Price: $349 – $399
Dedicated CPAP batteries
The Bluetti X30 is a purpose-built CPAP battery with 297Wh of LiFePO4 capacity and DC output cables for the AirSense 11. It bypasses the inverter entirely for maximum efficiency, delivering multiple nights of runtime without humidification.
NiteOwl CPAP Battery Backup (2nd Gen, 150Wh Swappable)
$329 – $379
Check price on AmazonThe NiteOwl is another dedicated CPAP battery backup that connects directly via DC. It is a straightforward option for AirSense 11 users who want a simple, purpose-built power source.
How to maximize battery runtime
The biggest factor isn't the battery — it's your AirSense 11 settings.
- Turn off the humidifier. This alone cuts power draw by 70%. Use a standalone room humidifier or nasal spray instead.
- Turn off the heated tube. If you keep the humidifier, at least disable the heated tube. It's the biggest single power drain.
- Use a DC cable instead of AC. Going DC-direct saves 10-15% of your battery capacity.
- Lower your pressure if your doctor allows it. Higher pressures use more power because the motor works harder.
- Use EPR (Expiratory Pressure Relief). EPR reduces pressure during exhale, which slightly lowers average power consumption.
Cables and adapters you need
The AirSense 11 uses a different power connector than the AirSense 10. Make sure any DC battery cable is specifically for the AirSense 11, not the 10.
- Medistrom to AirSense 11: Included with the Pilot-24 Lite (or buy separately ~$25)
- Generic DC cable: Look for "ResMed AirSense 11 DC cable 20V" — some third-party batteries ship these
- Car adapter: ResMed sells a 12V/24V DC converter for the AirSense 11 (~$65). Works with any car or RV 12V outlet.
For 12V car and RV power, a dedicated DC converter is the most efficient route — it steps your vehicle's 12V supply up to the 20V the AirSense 11 needs, with no AC inverter in the loop.
The HKY AirSense 11 DC converter plugs into any 12V cigarette-lighter socket and outputs the regulated 20V the machine expects. Our CPAP DC power adapter guide covers connector pinouts and how to avoid frying your machine with the wrong voltage.
AirSense 11 vs AirSense 10: battery differences
If you're upgrading from the AirSense 10, the good news: the AirSense 11 uses less power (65W power supply vs 90W). The bad news: it uses a different power connector, so your old DC cables won't fit.
The AirSense 11 also has a built-in battery mode that reduces power consumption when it detects DC input. This gives you about 15-20% more runtime compared to the AirSense 10 on the same battery.
Related reading
- Best battery for ResMed AirSense 10 — if you're upgrading from an AirSense 10
- Best CPAP backup batteries — full comparison across all machines
- CPAP battery backup guide — sizing math and compatibility primer
- CPAP battery travel checklist — everything to pack
- CPAP power outage guide — home backup strategies
- Best battery for ResMed AirCurve — same 24V connector, BiPAP-specific picks
- Best battery for ResMed AirMini (2026) — if you travel with the AirMini as a backup
What to do next
The AirSense 11 runs great on battery when you turn off the heated humidifier. Pick a battery sized for your actual nightly draw and cable for your specific connector.
- Flying or doing weekend trips: buy the Medistrom Pilot-24 Lite with the AirSense 11 DC cable for direct-DC efficiency under 100 Wh.
- Home outage protection: choose a 256 Wh+ power station with UPS mode so your therapy never skips a beat.
- Before your next trip, do an overnight test at home to confirm runtime with your actual pressure settings.
