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If you rely on a CPAP, a power outage at night is more than an inconvenience. CPAP machines use relatively little power, so a modest battery can cover a night or more if you plan for the heated humidifier and the way you connect.
This guide uses manufacturer specifications and published data. It is not medical advice: talk to your doctor and your equipment supplier about your backup plan, especially if you use other powered medical equipment.
CPAP power draw
- ResMed AirSense 11: ResMed's user guide lists a 65 W power supply, typical consumption of 56.1 W and peak of 73.2 W.
- Typical published range: about 30–60 W without heat and 60–120 W with a heated humidifier (Champion wattage chart).
- Heated humidifier: ResMed's DC converter guide says the humidifier uses considerably more power than the device alone. Turning heat off is the single biggest way to stretch a battery.
Your machine's exact draw depends on pressure settings, mask leak, humidity and tube heating. Check the label on your power supply and your device's manual.
Battery size for a CPAP
Nightly energy = watts × hours. Through a power station's AC outlet, divide by about 0.85 for inverter losses, then add 20% headroom.
| Setup | Wh per night | Battery per night | Nights on ~1 kWh |
|---|---|---|---|
| No heat, ~40 W | 320 | ≈ 452 Wh | ≈ 2 |
| No heat, ~60 W | 480 | ≈ 678 Wh | ≈ 1.5 |
| Heated humidifier, ~120 W | 960 | ≈ 1,355 Wh | < 1 |
So for one night with humidification off, a 500–700 Wh battery is a reasonable target; for three nights, about 1,400–2,000 Wh, or a smaller battery you can recharge by day from solar or a generator. The sizing quiz does this math with your own numbers.
DC vs. AC: connect the efficient way
A CPAP's power brick turns household AC into low-voltage DC (24 V on the AirSense 11). Running it from a power station's AC outlet means converting battery DC → AC → DC, losing energy twice. A manufacturer DC converter plugs into a 12 V outlet instead.
- ResMed sells a DC/DC converter (24 V / 90 W output from a 12 V or 24 V source) and the ResMed Power Station II battery, which ResMed markets for travel and power outages.
- Use only the converter or cable your CPAP's manufacturer specifies. Third-party adapters may not be approved for your machine.
- Many power stations have a 12 V car-style outlet that a CPAP DC converter can plug into. Check the station's 12 V output rating against the converter's requirements.
Power stations that fit CPAP use
Look for LiFePO4 chemistry, enough capacity for your nights, a 12 V DC outlet, and a fast UPS switchover so the machine doesn't stop if the power cuts out while you sleep. Note that some manufacturers state limits on medical use. Jackery's FAQ for the Explorer 1000 v2, for example, says it does not recommend the unit for medical or life-support devices. Read your station's manual.
Comparison: all picks in this guide
- 01One nightEcoFlow RIVER 3 Plus
A single night without heat, light enough to keep at the bedside.
- Capacity
- 286 Wh
- Cont./surge
- 600 / 1,200 W
- Chem./fuel
- LiFePO4 (LFP)
- Weight
- 10.4 lb
- 02Several nightsAnker SOLIX C1000
Two or more nights, plus phones and a router.
- Capacity
- 1,056 Wh
- Cont./surge
- 1,800 / 2,400 W
- Chem./fuel
- LiFePO4
- Weight
- 28.44 lb
- 03Heated humidifierEcoFlow DELTA 3 Plus
Users who need humidification or want to share power with other essentials.
- Capacity
- 1,024 Wh
- Cont./surge
- 1,800 / 3,600 W
- Chem./fuel
- LiFePO4 (LFP)
- Weight
- 27.6 lb
EcoFlow RIVER 3 Plus
One nightBest for A single night without heat, light enough to keep at the bedside.
286 Wh with a sub-10 ms UPS switchover in a 10.4 lb unit; expandable to 858 Wh with an add-on battery for more nights.
Strengths
- + UPS <10 ms
- + Small and quiet
- + Expandable to 858 Wh
Tradeoffs
- − ≈ 4 hours of a 60 W CPAP via AC. Use DC and no heat for a full night
- − Not enough for a heated humidifier
- Note: X-Boost runs some higher-watt resistive devices at reduced power (up to 1,200 W per EcoFlow).
| Capacity | 286 Wh |
| AC output | 600 W continuous / 1,200 W surge |
| Battery | LiFePO4 (LFP) |
| Weight | 10.4 lb |
| Max solar input | 220 W |
| Rated cycles | 3,000 cycles to 80% |
| AC outlets | 3 |
| UPS switchover | <10 ms |
| Expansion | Up to 858 Wh with an EcoFlow extra battery |
Specs from the manufacturer's page, checked Oct 27, 2026. Confirm details before you buy.
Anker SOLIX C1000
Several nightsBest for Two or more nights, plus phones and a router.
1,056 Wh LiFePO4 with a listed UPS switch time under 20 ms, six AC outlets and up to 600 W of solar input; expandable to 2,112 Wh.
Strengths
- + ≈ 2 nights at 56 W via AC
- + Expandable
- + Solar-ready
Tradeoffs
- − 28.4 lb
- − Check Anker's guidance on medical device use
- Note: A newer C1000 Gen 2 has different specs. Make sure the listing matches the model you want.
| Capacity | 1,056 Wh |
| AC output | 1,800 W continuous / 2,400 W surge |
| Battery | LiFePO4 |
| Weight | 28.44 lb |
| Max solar input | 600 W |
| Rated cycles | 3,000 cycles to 80%+ |
| AC outlets | 6 |
| UPS switchover | <20 ms |
| Expansion | Up to 2,112 Wh with the matching expansion battery |
Specs from the manufacturer's page, checked Oct 27, 2026. Confirm details before you buy.
EcoFlow DELTA 3 Plus
Heated humidifierBest for Users who need humidification or want to share power with other essentials.
1,024 Wh with <10 ms UPS, expandable to 5 kWh, and up to 1,000 W of solar input for daytime recharging.
Strengths
- + <10 ms UPS
- + Expandable to 5 kWh
- + High solar input
Tradeoffs
- − A heated humidifier still uses most of a 1 kWh battery per night
| Capacity | 1,024 Wh |
| AC output | 1,800 W continuous / 3,600 W surge |
| Battery | LiFePO4 (LFP) |
| Weight | 27.6 lb |
| Max solar input | 1,000 W |
| Rated cycles | 4,000 cycles to 80%+ |
| AC outlets | 6 |
| UPS switchover | <10 ms |
| Expansion | Up to 5 kWh with compatible EcoFlow extra batteries |
Specs from the manufacturer's page, checked Oct 27, 2026. Confirm details before you buy.
Your CPAP outage plan
- 01Find your machine's power specs and buy the manufacturer's DC converter if one exists for your model.
- 02Do a dry run: run the CPAP from your battery for one night while the grid is up, and note how much charge is left in the morning.
- 03Keep the battery charged and stored near the bed. Recharge it after any outage.
- 04Turn off the heated humidifier and heated tube during outages if your doctor agrees.
- 05Plan a way to recharge for longer outages: solar panels, a car, or a generator run safely outdoors.
- 06Tell your utility and your equipment supplier that you depend on powered medical equipment, and ask what support they offer.
FAQ
- How long will a CPAP run on a 1,000 Wh power station?
- About 15 hours at 60 W through AC (1,000 × 0.85 ÷ 60): roughly two 8-hour nights without heat. With a heated humidifier at around 120 W, expect one night or less.
- Can I use a car battery for my CPAP?
- Only with the manufacturer's approved DC cable or converter, and be aware that draining a car's starting battery may leave you unable to start the car. A dedicated LiFePO4 power station is the simpler option.
- Does the heated humidifier really matter?
- Yes. ResMed says the humidifier uses considerably more power than the device alone, and typical published ranges roughly double from 30–60 W to 60–120 W with heat.
- Is this medical advice?
- No. It's a power-planning guide based on manufacturer specs. Talk to your doctor and your equipment supplier about your therapy during outages.
Sources
- [1]ResMed AirSense 11 User Guide (power specifications) (accessed October 27, 2026)
- [2]ResMed Air10/S9 DC/DC Converter 90W user guide (accessed October 27, 2026)
- [3]ResMed: CPAP battery and power converters (accessed October 27, 2026)
- [4]Champion Power Equipment: Generator Wattage Chart (accessed October 27, 2026)
- [5]FSEC/UCF PV-GEMS Phase 1 Final Report (FSEC-CR-2116-21), submitted to U.S. DOE (December 15, 2021)
- [6]Product specs: each manufacturer's product page, linked on every pick, checked October 27, 2026.
Related guides
- Best Portable Power Stations for Power Outages (2026) →Six LiFePO4 picks from phone-and-CPAP size to whole-home scale, with runtime math for each.
- What Size Power Station You Need: The Sizing Math, Worked Through →Four-step sizing math with worked examples. It is the same method our quiz uses.
- Best Solar Generator Kits for Long Power Outages (2026) →Power station + panel bundles that recharge without fuel, with the math on how much sun you really need.
- Power Station vs. Generator: Runtime, Watts, Safety and Cost Compared →Side-by-side comparison of batteries and fuel generators, and why many homes end up with both.
Planning the rest of your outage kit? Visit the Outage prep hub: PowerLockdown or The Blackout Kit on PowerLockdown.