What to know before buying a CPAP backup battery
CPAP machines vary a lot in how much power they draw. Before picking a battery, you need to know your machine's actual consumption — not the number on the power supply label.
The power supply rating is the maximum the machine can ever draw. Real-world usage is much lower. Here are typical averages:
| Machine | Without humidifier | With humidifier + heat |
|---|---|---|
| ResMed AirMini | 6-7W | N/A (passive HumidX only) |
| ResMed AirSense 11 | 8-15W | 30-55W |
| Philips DreamStation 2 | 5-10W | 25-50W |
| Philips CPAP (legacy) | 15-25W | 40-70W |
For an 8-hour night, multiply your average watts by 8 to get the watt-hours you need. Add 20-30% buffer for cold temperatures, high pressure, or battery aging. New to portable CPAP power? Read our full CPAP battery backup guide for sizing formulas, AC vs DC efficiency, and machine-by-machine compatibility before you shop.
Rule of thumb:
- CPAP only (no humidity): 150-250 Wh for one night
- CPAP with humidifier: 300-500 Wh for one night
- ResMed AirMini: 50-60 Wh for one night
Best backup batteries for CPAP in 2026
Best travel CPAP battery: Medistrom Pilot-24 Lite
The Medistrom Pilot-24 Lite is the go-to for anyone who flies with their CPAP. At 97.68 Wh, it stays under the FAA's 100 Wh carry-on limit without needing airline approval. It connects directly to compatible ResMed and other machines via DC, cutting out the conversion losses you get with a power station.
The result is better runtime per dollar than most alternatives. For an AirMini, you get about 14-16 hours (two nights). For an AirSense 11 without humidification, expect 6-10 hours depending on your pressure settings.
It's not cheap at around $290, but it's the product most CPAP travelers settle on after one bad trip with the wrong battery.
Best for: Air travel, light packing, one or two night trips Capacity: 97.68 Wh Weight: 1.4 lbs FAA approved: Yes
Best CPAP battery under $200: EcoFlow RIVER 2
The EcoFlow RIVER 2 packs 256 Wh and charges from zero to full in about 60 minutes. For a CPAP user, that's 8-10 hours of therapy without humidification, or about 4-5 hours if you run the heated humidifier.
The LiFePO4 battery chemistry gives it 3,000+ charge cycles before hitting 80% capacity. Buy it today and it'll likely outlast your CPAP machine. The pure sine wave AC output handles any CPAP cleanly with no compatibility issues.
Solar-compatible too, which matters if you camp without hookups. Pair it with a 110W foldable panel and you can recharge mid-trip.
Best for: Camping, road trips, home outage backup Capacity: 256 Wh Weight: 7.7 lbs FAA approved: No
Best CPAP battery for power outages: Bluetti AC2A
The Bluetti AC2A has one feature that sets it apart for home backup: UPS mode. Keep it plugged into the wall and it charges automatically. When your electricity fails, it switches to battery in under 20 milliseconds. Your CPAP doesn't skip a beat.
LiFePO4 chemistry means it handles daily charge-discharge cycles without degrading fast. At around $150, it's also the most affordable LiFePO4 option on this list. The 204 Wh capacity covers most CPAPs for a full night without humidification.
Best for: Home power outage protection, always-on backup Capacity: 204 Wh Weight: 7.5 lbs FAA approved: No
Best budget CPAP battery: Jackery Explorer 240 v2
The Jackery Explorer 240 v2 is the reliable workhorse in this category. 241 Wh, clean sine wave output, 5.2 lbs, and around $200. It's not the fastest charger and it uses Li-ion instead of LiFePO4, but it's proven reliable across thousands of CPAP users.
For one night of CPAP-only therapy it's plenty. For multi-night camping you'd want more capacity. It's a solid starter battery if you want a trusted brand without a lot of research.
Best for: Budget buyers, one-night backup, first CPAP battery Capacity: 241 Wh Weight: 5.2 lbs FAA approved: No
Best CPAP battery for multi-night camping: Jackery Explorer 300
The Jackery Explorer 300 steps up to 293 Wh in a 7.1-lb frame. For a CPAP drawing 25W without humidification, that's 9-12 hours of runtime, or roughly 1-2 solid nights. Run the humidifier and you get 5-6 hours, just enough for one night.
The bigger win is using it alongside a solar panel for camping without shore power. Pair it with a 100W foldable panel and you can fully recharge it in a few hours of sun, making multi-week off-grid trips possible.
Best for: Extended camping, solar setups, multi-night trips Capacity: 293 Wh Weight: 7.1 lbs FAA approved: No
Side-by-side CPAP backup battery comparison
| Battery | Capacity | Chemistry | Weight | Runtime (no humidity) | Runtime (with humidity) | UPS Mode | Price | FAA OK? |
|---|---|---|---|---|---|---|---|---|
| Medistrom Pilot-24 Lite | 97.68 Wh | Li-ion | 1.4 lb | 6-13 hrs | 2-3 hrs | No | ~$290 | Yes |
| Bluetti AC2A | 204 Wh | LiFePO4 | 7.5 lb | 7-9 hrs | 3-5 hrs | Yes | ~$150 | No |
| Jackery Explorer 240 v2 | 241 Wh | Li-ion | 5.2 lb | 8-10 hrs | 4-5 hrs | No | ~$200 | No |
| EcoFlow RIVER 2 | 256 Wh | LiFePO4 | 7.7 lb | 8-10 hrs | 4-5 hrs | No | ~$200 | No |
| Jackery Explorer 300 | 293 Wh | Li-ion | 7.1 lb | 9-12 hrs | 5-6 hrs | No | ~$250 | No |
Runtime estimates assume 25W draw without humidifier, 50W with heated humidifier. Dedicated CPAP batteries with DC-direct connections run 10-20% more efficient than AC power stations.
How to pick the right CPAP backup battery
Flying with your CPAP? The Medistrom Pilot-24 Lite is the only viable carry-on battery here. Everything else is over 100 Wh and can't fly without special approval or at all.
Protecting against power outages at home? Get the Bluetti AC2A. The UPS mode handles failover automatically, and the LiFePO4 chemistry means it'll hold up for years of standby use.
Going camping without hookups? The EcoFlow RIVER 2 is the best value — 256 Wh, fast charging, solar-compatible, and durable chemistry. It can be fully recharged from a 110W panel in 2-3 hours of direct sun.
On a tight budget? The Jackery Explorer 240 v2 at ~$200 is the most sensible entry point. It's been around long enough to have a strong reputation and is unlikely to surprise you.
Tips for getting more CPAP battery runtime
- Turn off the heated humidifier. It's the single biggest power draw on most machines. Even dropping humidity from 4 to 2 cuts your consumption significantly.
- Use DC connection when possible. If your battery has a DC output and your CPAP takes a matching cable, use it. Skipping the AC conversion saves 10-20%.
- Fix mask leaks. A leaky mask makes your machine work harder and draws more power. Tighten up your seal.
- Keep the battery warm. Cold kills battery capacity. In below-40-degree weather, store the battery inside until bedtime.
- Start fully charged. Simple but easy to forget. Always charge your battery before a trip or a storm season.
CPAP battery backup for power outages: UPS mode and auto-failover
If your main concern is keeping your CPAP running during power outages, you need a different setup than a traveler. The goal is an always-ready battery that switches over instantly when the lights go out — no waking up, no plugging in cables at 2 AM.
How UPS mode works for CPAP
UPS stands for uninterruptible power supply. A battery with UPS mode sits between the wall outlet and your CPAP, passing through grid power while keeping itself charged. When the power drops, it switches to battery in under 20 milliseconds. Your CPAP never notices.
Not every portable power station has UPS mode. Many have "pass-through charging," which is different — pass-through lets you charge the battery while using it, but there's no guaranteed switchover speed. When the power cuts, you might get a 500ms-2s gap. Some CPAPs will restart from scratch. Others will alarm and stop therapy.
Batteries with true UPS mode for CPAP:
- Bluetti AC2A — under 20ms switchover, LiFePO4, 204 Wh (~$150)
- Bluetti AC70 — under 20ms switchover, LiFePO4, 768 Wh (~$500) — enough for 2-3 nights with humidifier
- EcoFlow DELTA 2 — under 30ms switchover, LiFePO4, 1024 Wh (~$600) — serious whole-night-with-humidity capacity
How to set up always-on CPAP backup at home
Here's the step-by-step setup for uninterrupted CPAP therapy during outages:
- Place the battery on your nightstand or under the bed. It stays plugged into the wall 24/7.
- Plug your CPAP's power adapter into the battery's AC outlet (or use a DC cable if the battery supports it).
- Verify UPS mode is enabled. On the Bluetti AC2A, this is a toggle in the Bluetti app. On some units, it's a physical switch.
- Test the failover. With your CPAP running, unplug the battery from the wall. Your CPAP should keep running without pausing, restarting, or alarming. If it hiccups, you have pass-through, not UPS.
- Check the battery monthly. Confirm it's holding charge and the firmware is current. LiFePO4 batteries handle this standby duty well, but Li-ion batteries degrade faster when kept at 100% continuously.
How long will a CPAP backup battery last during an outage?
Depends on your draw. Here's what to expect with CPAP-only (no humidity) at a typical 20W draw:
| Battery | Capacity | Estimated outage runtime |
|---|---|---|
| Bluetti AC2A | 204 Wh | 8-10 hours |
| Bluetti AC70 | 768 Wh | 30-38 hours |
| EcoFlow DELTA 2 | 1024 Wh | 40-50 hours |
For extended multi-day outages (ice storms, hurricanes), pair a UPS battery with a solar panel so you can recharge during the day and run your CPAP at night indefinitely.
Li-ion vs LiFePO4: which CPAP battery chemistry is better?
Battery chemistry is the most underrated factor when choosing a CPAP backup battery. The two types you'll see are lithium-ion (Li-ion) and lithium iron phosphate (LiFePO4). They look the same from the outside but behave very differently over time.
Cycle life
This is the biggest difference. Cycle life is how many full charge-discharge cycles a battery survives before it drops to 80% of its original capacity.
- Li-ion: 500-800 cycles typical. If you use it weekly, that's roughly 8-12 years. If you use it daily (like a UPS), it might last 1.5-2 years before noticeable degradation.
- LiFePO4: 2,500-3,500+ cycles typical. Daily use still gives you 7-10 years. Weekly use means it'll likely outlast you.
For a bedside UPS that cycles daily or stays at full charge on standby, LiFePO4 is the clear winner.
Standby performance
Li-ion batteries degrade faster when stored at 100% charge for long periods — exactly what a UPS does. LiFePO4 handles full-charge standby much better. If your battery will sit plugged in for months between outages, LiFePO4 will hold up while Li-ion slowly loses capacity.
Weight and energy density
Li-ion packs more energy per pound. That's why the Medistrom Pilot-24 Lite (Li-ion) weighs only 1.4 lbs for 97.68 Wh, while the Bluetti AC2A (LiFePO4) weighs 7.5 lbs for 204 Wh. For travel, Li-ion's weight advantage matters. For a nightstand battery, it doesn't.
Temperature tolerance
LiFePO4 handles heat better and has a wider safe operating range. In hot climates or if your battery sits near a heating vent, LiFePO4 is more stable. Both chemistries lose capacity in extreme cold, but LiFePO4 recovers better once warmed.
Which chemistry should you pick?
| Factor | Li-ion | LiFePO4 |
|---|---|---|
| Cycle life | 500-800 | 2,500-3,500+ |
| Weight per Wh | Lighter | Heavier |
| Standby degradation | Degrades faster at 100% | Handles standby well |
| Cost per Wh | Lower | Higher (but falling) |
| Best use case | Travel, infrequent use | Home backup, daily use, UPS |
Bottom line: If you fly or backpack, Li-ion saves weight. If the battery lives on your nightstand or goes camping regularly, LiFePO4 pays for itself in longevity.
Solar charging a CPAP backup battery
Solar makes your CPAP battery effectively unlimited for camping, RV living, or extended outage preparedness. But panel sizing matters — undersize it and you'll never fully recharge between nights.
How much solar do you need for CPAP?
Start with your nightly consumption and work backward:
- CPAP-only (no humidity): ~150-200 Wh per night
- CPAP with humidifier: ~300-400 Wh per night
Solar panels produce their rated wattage only in direct, full sun. Real-world output is typically 60-80% of the panel's rating due to angle, clouds, and temperature. And you get roughly 4-6 peak sun hours per day in most of the US during summer.
The math for CPAP-only:
- Need to replace: 200 Wh
- Peak sun hours: 5 (average)
- Real-world efficiency: 70%
- Panel size needed: 200 ÷ (5 × 0.70) = 57W minimum
A 100W panel gives you comfortable margin. A 60W panel works on clear days but won't keep up in overcast weather.
The math for CPAP with humidifier:
- Need to replace: 400 Wh
- Panel size needed: 400 ÷ (5 × 0.70) = 114W minimum
You'll want a 200W panel or a pair of 100W panels for humidifier use.
Which CPAP batteries accept solar input?
Most portable power stations accept solar via an XT60 or Anderson connector. Dedicated CPAP batteries (like the Medistrom) generally don't support solar.
| Battery | Solar input | Max solar wattage | Recommended panel |
|---|---|---|---|
| Medistrom Pilot-24 Lite | No | N/A | N/A |
| Bluetti AC2A | Yes | 200W | 100-200W |
| EcoFlow RIVER 2 | Yes | 110W | 100-110W |
| Jackery Explorer 240 v2 | Yes | 100W | 60-100W |
| Jackery Explorer 300 | Yes | 100W | 100W |
Solar charging tips for CPAP campers
- Angle the panel toward the sun. Laying it flat on the ground wastes 20-30% of potential output. Prop it up or use an adjustable stand.
- Start charging early. Set the panel up at sunrise, not after lunch. Midday hours produce the most power, but morning hours add up.
- Keep the panel cool. Solar panels lose efficiency in extreme heat. If the panel is too hot to touch, it's losing 10-15% output. Elevate it for airflow.
- Carry a backup plan. Two cloudy days in a row and you're in trouble. Bring a car charger cable as a fallback — most batteries can charge from a 12V vehicle outlet.
- Match the panel to the battery brand when possible. EcoFlow panels with EcoFlow batteries, Jackery with Jackery — you'll get optimized MPPT tracking and sometimes faster charge rates.
Common CPAP backup battery mistakes
These mistakes cost people sleep, money, or both. Avoid them.
Running a heated humidifier on a small travel battery
This is the most common mistake. A heated humidifier draws 30-55W on top of your CPAP's base draw. A 100 Wh travel battery that lasts 10+ hours without humidity might die in 2-3 hours with it cranked up. If you're using a battery under 250 Wh, turn the humidifier off or set it to the lowest setting. Use a HumidX or similar passive humidity insert instead.
Ignoring depth-of-discharge limits
Draining a battery to 0% regularly shortens its life dramatically. Li-ion batteries should ideally stay above 20%. LiFePO4 can handle deeper discharges but still lasts longest if you keep it above 10%. Size your battery so that a full night of CPAP use brings it down to 20-30%, not 0%. This means buying a battery rated for 130-150% of your actual nightly consumption.
Not testing before a trip
You don't want to discover your battery can't power your CPAP at a campsite in the dark. Run a full overnight test at home first. Plug your CPAP into the battery, set everything to your normal therapy settings, and sleep on it. Check the remaining charge in the morning. Now you know exactly what you're working with — no guesswork.
Assuming the label capacity equals usable capacity
A battery rated at 256 Wh doesn't give you 256 Wh of usable power to your CPAP. There are conversion losses (DC to AC and back), inverter overhead, and the battery management system reserves a small percentage to protect the cells. Expect 80-90% of the rated capacity to actually reach your machine. A 256 Wh battery delivers roughly 200-230 Wh of real therapy power through AC.
Leaving a Li-ion battery at 100% for months
If you bought a backup battery "just in case" and it sits on a shelf at full charge for a year, a Li-ion battery will degrade noticeably. Store Li-ion batteries at 50-60% charge if they won't be used for more than a month. LiFePO4 is more tolerant of full-charge storage, which is another reason it's better for standby backup duty.
Buying a battery with no pure sine wave output
Cheap inverters and some older power stations use modified sine wave output. Most modern CPAP machines require pure sine wave to run properly. A modified sine wave can cause buzzing, overheating, or outright refusal to start. Every battery on this page produces pure sine wave, but if you're shopping elsewhere, verify this spec before buying.
Related reading
- CPAP battery backup guide — the full primer on sizing, chemistry, and compatibility
- CPAP battery sizing guide — calculate exactly how many Wh you need
- Best battery for ResMed AirMini 2026 — dedicated AirMini picks
- Best battery for ResMed AirSense 11 — dedicated AirSense 11 picks
- CPAP power outage guide — home backup and UPS strategies
- LiFePO4 vs Li-ion CPAP battery — pick the right chemistry
What to do next
Pick the battery that matches your primary use case and then test it at home before you actually need it. A quick next-step checklist:
- Measure your CPAP's real power draw for one full night, then match it to the runtime math above before buying.
- Order the pick that fits your use case — Medistrom Pilot-24 Lite for flying, Bluetti AC2A for home UPS, EcoFlow RIVER 2 for camping.
- Run a full overnight test at home so you know exactly how many hours you get before a trip or outage.
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