The right battery picks up your CPAP mid-breath when the grid quits, and runs it silently till morning. We modeled 61 stations — humidifier on and off, AC and 12 V DC — to find the ones that actually reach sunrise.
Researched & scored by Brennan Noailles·Written by Ian Schneider·How we test →
Picked on the specs that decide a night — cutover speed, bedside noise, LiFePO4 endurance — at three sizes of night. The planner below sizes your exact machine and settings.
Travel & weekends
The one you actually pack.
288 Wh · 8 lb · 10 ms cutover · 12 V/10 A socket · LiFePO4
Eight pounds, with a verified 12 V car socket for your machine’s DC cord: about three heat-off nights on that silent path, or half a humidified one. Jackery doesn’t state a noise figure; if you sleep light, Anker’s SOLIX C300 is a verified 25 dB for a pound more and about $60 more.
The nightly bedside UPSwhat most readers need
Plugged in, forgotten, ready.
1,024 Wh · 10 ms cutover · 30 dB · LiFePO4
Sits between the wall and your machine. When the grid fails it takes over in 10 milliseconds, beneath your machine’s notice and yours. A night and a half humidified, six with the heat off.
Long outages & off-grid
Quieter than your fridge, for nights on end.
≈2 kWh · 10 ms cutover · 16 dB · solar-ready
At 16 dB it is close to silent beside a bed, and two kilowatt-hours is three humidified nights, or the CPAP plus the fridge through a long outage.
Why some batteries carry you silently to morning — and others wake you at 3 a.m. One night, hour by hour: four things decide it, and only one of them is capacity.
11:04 PM
The blower that pushes your air is a tiny brushless motor — it sips around 10 watts. What actually drains your battery is heat. The humidifier's heater plate and the heated hose are resistive elements — electrically, a small kettle — and warming water all night takes far more energy than moving air. Together they pull 30–45 watts of pure heat, which is why the humidifier and tube account for up to ~80% of a running machine's draw. Left on, they turn a four-night battery into a one-night battery.
That's the single most useful fact for sizing: "watts with the humidifier on" is the only number worth planning around, and switching the heat off in an outage can stretch the same battery roughly five times further.
Where a CPAP's watts go
Field note
12:52 AM
Look at your power brick: it turns wall AC into low-voltage DC — 24 V on most ResMed machines — before a single breath. Run the machine off a power station's AC outlet and you convert twice: the battery's DC up to 120 V AC, only for the brick to rectify it straight back to DC, losing 15–25% to the round trip.
Worse for a sleeper, the inverter's cooling fan runs all night a foot from your head. A model-specific DC converter cable into the station's 12 V port skips both conversions — 15–25% more runtime, and silence.
3:17 AM
A CPAP's power supply rides through a few milliseconds of dropout on its internal capacitors. A power station in true UPS/EPS mode that switches to battery in under ~20 ms beats that window — the machine never reboots, and you sleep straight through.
A plain battery (or a sluggish "UPS" that takes 50–500 ms) lets the CPAP brown out: it reboots, restarts its pressure ramp, and wakes you. This is the difference between "has a battery" and "medical backup" — the cutover speed is the entire game.
When the grid blinks: does your CPAP notice?
The spec that matters
6:41 AM
The math is simple: your average watts × the hours you sleep, divided by efficiency (~85% effective through an inverter once you count its own overhead, ~95% on DC). A humidified 55 W setup over 8 hours is ~440 Wh on DC, ~520 Wh through an inverter — so a "500 Wh" station is really a one-night unit with the humidifier on.
Two wrinkles worth knowing: at altitude the blower spins faster to hold your prescribed pressure, nudging the draw up; and running heat-off to save power trades comfort — a dry throat, or "rainout" condensation in the hose — for runtime. It's a fine emergency move, not an every-night one.
Sources: CPAP component power breakdown (Enticare ENT, UDPOWER); ResMed AirSense DC/wattage figures; UPS switchover & device-reboot thresholds (Sleep Backup Lab, EcoFlow). Figures are typical ranges — check your machine's label and manual.
Tell it your machine and your nights — or yours and your partner's. It answers with the stations that survive them, and the exact outlet each machine plugs into.
Heat off ≈ 3–5× the nights12 V DC is silent, +15–25%Under 20 ms or it reboots
Choose the model — every number below follows from its draw.
The link reopens this planner with your exact setup.
To sleep 1 night, you need
≈566 Wh per night as configured
heat off: ≈139 Wh — your biggest lever
Our pick for this setup
858 Wh · 10 ms cutover · 30 dB · $359
Charge left, hour by hour
Reaches 7:00 AM with ≈34% left · heat off: ≈84% left.
Estimates, not guarantees. Assumes 90% of rated capacity usable, 88% inverter efficiency plus ~6W inverter overhead on the AC path, 95% on the DC path. Typical draws from manufacturer power-supply ratings (e.g. ResMed 90W PSU ceiling) and owner-reported overnight measurements: an AirSense 11 with heated humidifier + tube averages ~50–57W (85W peaks) and ~10–15W with heat off. Check the label on your own power brick — pressure and humidity level move the real number.
Nights of ResMed AirSense 11 runtime (8-hour nights) on stations that cut over in 15 ms or less and stay at or under 40 dB. Any machine of similar draw lands close; the planner above models your exact setup, including two machines.
| Station | Humidifier on · AC | Heat off · AC | Heat off · 12V DC |
|---|---|---|---|
| EcoFlow RIVER 3 PLUS$299 | ≈0.5 | ≈1.9 | no 12V socket |
| Anker SOLIX C300$329.99 | ≈0.5 | ≈1.9 | ≈3.1 |
| BLUETTI Elite 30 V2$249.99 | ≈0.5 | ≈1.9 | ≈3.1 |
| Anker SOLIX C300X$299.99 | ≈0.5 | ≈1.9 | no 12V socket |
| Jackery Explorer 300 v2$269 | ≈0.5 | ≈1.9 | ≈3.1 |
| EcoFlow RIVER 3 MAX$499 | ≈0.9 | ≈3.7 | no 12V socket |
| EcoFlow RIVER 3 MAX PLUS$359 | ≈1.4 | ≈5.6 | no 12V socket |
| EcoFlow DELTA 3 1000 Air$309 | ≈1.5 | ≈6.2 | no 12V socket |
| Goal Zero Yeti 1000 (6th Gen)$1,199.95 | ≈1.6 | ≈6.4 | no 12V socket |
| Jackery HomePower 1000 Plus v2$749 | ≈1.6 | ≈6.6 | no 12V socket |
Short answers to the questions that actually block a purchase.
Generally, no. TSA and FAA regulations strictly limit lithium batteries to 100Wh (or 160Wh with airline pre-approval). Since a typical CPAP requires at least 300Wh to last a full 8-hour night with a humidifier, most power stations are legally grounded. The best strategy is to carry a flight-approved 'travel battery' like the Medistrom Pilot-24 for the flight itself, and have your larger power station waiting at your destination or shipped ahead.
Field note
Absolutely, provided the unit supports EPS/UPS (Uninterruptible Power Supply) pass-through. Modern LiFePO4 (LFP) units from brands like EcoFlow or Anker are designed exactly for this. They switch to battery power in under 20 ms if your wall power fails (10 ms on this guide's short-list picks), ensuring your CPAP never skips a breath. Because LFP chemistry lasts for 3,000+ cycles (10+ years of daily use), you won't 'wear out' the battery by keeping it plugged in.
Field note
Most modern units stay under 30dB (whisper-quiet) at the low wattage a CPAP draws. However, the fan kicks in when the internal inverter gets hot. The key to silence is bypassing the AC inverter completely by using a DC-to-DC cable.
Field note
It depends entirely on your humidifier settings. A 500Wh unit (like the Jackery 500) will typically last 1 night with heat and humidity turned on, or 3-4 nights if you turn the humidifier off and use a DC adapter. Always look for a unit with at least 20% more capacity than your math dictates to account for 'inverter conversion loss' and battery degradation over time.
Yes, this is non-negotiable. Medical devices are sensitive electronics. A 'Modified Sine Wave' (found in cheap, generic batteries or old vehicle inverters) provides choppy power that can cause motor hum, excess heat, or permanently damage your machine’s motherboard. All major brands we recommend (EcoFlow, Bluetti, Jackery) use Pure Sine Wave inverters that cleanly mimic the power from your home wall outlet.
Yes — this is how you run indefinitely off-grid. A 100W or 200W portable solar panel can usually top off a 500Wh station in 4-6 hours of direct sunlight, which allows for indefinite off-grid CPAP use without ever needing a wall outlet. For the best results, use a power station with an MPPT (Maximum Power Point Tracking) solar charge controller, which pulls 30% more energy from the panels.
Yes — output is never the issue (two machines draw 20–120W combined, well within any station's AC rating). Capacity is: add both machines' draws and size for your target nights — two heated ResMed setups need roughly 1,000Wh per 8-hour night, or around 200Wh with both humidifiers off. Ports are the real catch: most stations have only ONE 12V car socket, and CPAP DC converters plug into a car socket — not the DC5521 barrel outlets — so the cleanest two-machine layout is one machine on the 12V socket and the second on an AC outlet.
Field note
This is the biggest efficiency lever in CPAP camping. Using the AC outlet wastes about 15–25% of your battery's energy just converting the DC battery power into AC wall power, only for your CPAP power brick to convert it back to DC. Buying a specific DC power cord for your CPAP (e.g., ResMed AirSense 10/11 DC Cable) allows you to plug directly into the 12V port, skipping the conversion and giving you significantly more runtime.
Top 3 per price range · Ranked by Sleep Therapy Reliability
The same battery, in the other situations it has to keep running.
Switchover speed is the spec that decides both. A CPAP is simply the highest-stakes thing you can put behind a UPS.
See UPS picks →A CPAP through a multi-day outage stops being a switchover question and becomes a capacity one.
Read the outage guide →Same machine, different problem — overnight power where there is no outlet within a mile.
See camping picks →Whichever station you choose, prove it before you depend on it. One quiet weeknight is all it takes.
Buy the DC cable with the battery, not during the trip. The model-specific 12 V converter cable is what unlocks silent, inverter-free running — it belongs in the drawer before you ever need it.
Sleep one full night on battery alone, at home. Charge to 100%, unplug the wall, use your normal settings — humidifier and all — and just go to bed.
Read the percentage in the morning. That number is your real margin — trust it over every calculator, including ours. If it makes you nervous, so will the third night of an outage.
Every spec on one grid — cutover, noise, capacity, ports.
