How many nights will a power station run your CPAP?
A real runtime answer in under a minute. Set your humidifier and hours — or enter your machine's own average draw — choose DC or AC, and we do the honest math against every station we track.
Where our answer stops
This is an electrical calculation, not medical advice
BatteryRank has no medical expertise and claims none. We compute whether a battery can supply the power your device's own label states — that is an electrical question, not a medical one.
This tool converts your machine's own draw into nights of runtime. It does not tell you whether a night without therapy is acceptable, whether pressure or humidifier settings should be changed to stretch a battery, or whether your machine is rated to run from an inverter. Those three are for your equipment supplier and the clinician who set the prescription — a longer number here is not permission for any of them.
A 256Wh-class station covers your 3-day need.
- You need (battery side)
- 240Wh battery-side
- Running load
- 9W
How we got there
| Device | Avg draw | Over 3 nights |
|---|---|---|
| CPAP (humidifier off) (DC) | 9W | 216Wh |
| Devices total | 216Wh |
On top of the device total, each station is charged its real conversion losses — AC loads ÷ inverter efficiency (0.85 typical, by chemistry), DC loads ÷ 0.9 — and capacity is counted from the best number we have for that unit: lab-measured usable, else the manufacturer's usable figure, else rated × 0.9 depth-of-discharge. No vague “reserve” padding — every derate is named in the methodology.
Lowest-capacity passing pick in our target margin band; otherwise the smallest passing unit.
- Runs your kit
- 3.6 nights
- AC delivered (est.)
243 Whest.. Show source
estimated sourceus.ecoflow.com ↗2026-07-04 · AC estimate from sourced battery capacity and the published efficiency assumption- Weight
4.72 kg. Show source
claimed sourceus.ecoflow.com ↗2026-07-04
- capacity covers the plan
- continuous output covers the running load
One size up, for when it runs longer than planned.
- Runs your kit
- 5 nights
- AC delivered (est.)
381 Whest.. Show source
estimated sourcesupport.bluettipower.com ↗2026-07-27 · AC estimate from sourced battery capacity and the published efficiency assumption- Extra vs right-size
- +1.5 nights
- Weight
6.7 kg. Show source
claimed sourcesupport.bluettipower.com ↗2026-07-27
- capacity covers the plan
- continuous output covers the running load
Scenario: CPAP nights — 3 nights · humidifier off · ~9W preset · DC path Duration: 3-day Energy need (battery side): 240Wh usable Running load: 9W Recommended minimum: 256Wh class,
Your inputs: 8h/night × 3 nights · humidifier off · ~9W preset · DC path (manufacturer converter, skips inverter loss). Bookmark or share this URL — it re-runs these exact inputs.
Sensitivity: flip humidifier on · try AC instead to see how much the answer moves. The humidifier toggle alone is ~6×.
Why the humidifier changes everything
The CPAP motor itself sips power — a typical machine is about 9W on the DC path, or roughly 72Wh across an 8-hour night. Add the heated humidifier and heated tube and the average jumps to around 56W (about 450Wh a night) — five to six times as much. That one setting is the difference between a small station lasting a week and lasting a single night. Every wattage here is sourced per device; open any result’s detail to see the source and date.
CPAP power questions, straight answers
- How many nights will a power station run a CPAP?
- It depends almost entirely on the heated humidifier. With the humidifier off and a DC adapter, a typical CPAP draws only about 9W — roughly 72Wh over an 8-hour night — so even a 500Wh-class station covers several nights. Turn the heated humidifier and tube on and the draw jumps to ~56W (about 450Wh a night), cutting the same station to roughly one night. This tool distinguishes battery-side energy from AC-delivered energy.
- Should I run my CPAP off DC or AC to save battery?
- DC, if your machine supports it. Running the CPAP from the station's 12V/DC output via the manufacturer's converter skips the inverter, which otherwise wastes about 15% turning battery DC into household AC. Over a multi-night trip that saved energy is a meaningful number of extra hours. Choose the path below — DC assumes the manufacturer's 12V/24V converter; AC pays full inverter losses — and the result states which one it used.
- Does turning off the humidifier really matter that much?
- Heated humidification changes power consumption, so we show separate manufacturer-based presets. Use the settings prescribed for your therapy when planning energy; this calculator does not advise changing humidification or treatment settings.
- Is a power station safe to run a CPAP overnight next to my bed?
- Use the machine manufacturer’s supported power connection and follow the station’s placement and ventilation instructions. Chemistry alone does not establish bedside suitability. Check low-load output behavior and keep your existing clinical backup plan.