Power It Up: running a CPAP overnight on a power station

Q: Can I run a CPAP from a 300 Wh station?

Often for part of a night. At an example 40 W average you'd get roughly 4–5 hours of AC runtime from a 245Wh unit. With the humidifier off and a lower draw, a full night may fit.

Q: Is AC or DC better for a CPAP?

DC through the maker's own cord or converter avoids inverter losses, so the same battery lasts longer. Use only accessories the CPAP maker approves.

Q: Where do I go next?

Try the power planner to put numbers to your own situation, or see the product picks on the deals page .

How many watt-hours a CPAP needs for an 8-hour night, with and without the humidifier, and the smallest power station that covers it.

Published October 30, 2026 · Updated November 2, 2026

Quick answer

A CPAP's draw depends heavily on the heated humidifier. As an example, a machine averaging 40 W for 8 hours needs about 320 Wh, more than a 245Wh RIVER 3 can deliver through its AC outlet but well within any 1kWh-class station. Check your machine maker's battery guide for its real draw.

Key points

CPAP energy use = average watts × hours of sleep.
The heated humidifier and heated tube are usually the biggest part of the draw.
A 1kWh-class station covers one or more nights; a 245Wh unit covers low-draw nights only.

What a CPAP draws

Item	Example figure	Where it comes from
CPAP power supply rating	Often 60–90 W on the brick	The most the supply can deliver, not the average draw
Average draw, humidifier off (example)	15–20 W	Example only; check the manufacturer's battery guide
Average draw, humidifier on (example)	40 W	Example only; varies with settings and room temperature
8-hour night at 40 W	320 Wh	40 × 8

How we do the math

Runtime (hours) ≈ usable watt-hours ÷ the device's average watts. Our reference set is five portable power stations whose specs we compiled in the Spec Check series. Estimated usable AC energy (our estimate: usable ≈ rated Wh × 0.80 (usable depth, Victron LiFePO4 data) × 0.92 (inverter, the NREL PVWatts manual derate) ≈ 0.736. Applying these to a power station gives a planning estimate, not a measurement): RIVER 3 ≈180Wh, DELTA 3 ≈754Wh, Anker C1000 ≈777Wh, Jackery 1000 v2 ≈788Wh, BLUETTI AC180 ≈848Wh.

Every device wattage on this page is an example. Read your own device's label or EnergyGuide sticker, or measure it with a plug-in energy meter, then put your number into the Power Planner.

Runtime on each reference station

Power station	Est. usable Wh	Est. runtime
EcoFlow RIVER 3	≈180	≈4.5 h
EcoFlow DELTA 3	≈754	≈18.9 h
Anker SOLIX C1000	≈777	≈19.4 h
Jackery Explorer 1000 v2	≈788	≈19.7 h
BLUETTI AC180	≈848	≈21.2 h

The smallest station that fits

At the 40 W example, the RIVER 3 covers about 4.5 hours, so it suits a full night only if your machine averages roughly 22 W or less (for example with the humidifier off). Check that against your maker's figures. For a full night with the humidifier, the smallest reference station that fits is a 1kWh-class unit. The DELTA 3 has the smallest capacity of those and the fastest published backup switchover (<10 ms). Many CPAP makers also sell a DC power cord or converter; running from DC skips the inverter loss.

EcoFlow RIVER 3 (245Wh)

Fits low-draw nights with the humidifier off; check your machine's average watts first.

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EcoFlow DELTA 3 (1,024Wh)

A full night with the humidifier at the 40 W example, with room to spare.

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Tips for longer runtime

Use the CPAP maker's DC cord where available.
Turn off unused AC outlets on the station; inverters draw some power just by being on.
Recharge during the day from the wall, a car or solar.

A CPAP is medical equipment. Ask your equipment supplier or doctor before changing settings or power sources.

FAQ

Can I run a CPAP from a 300 Wh station?

Often for part of a night. At an example 40 W average you'd get roughly 4–5 hours of AC runtime from a 245Wh unit. With the humidifier off and a lower draw, a full night may fit.

Is AC or DC better for a CPAP?