What You Need to Power a CPAP Overnight (Camping + Outages)

Last verified 2026-08-28 · every wattage cites its source · methodology

A cpap machine, device only — no humidifier alone needs 90 running watts and 90W available at startup — with 20% headroom, look for a generator rated around 200W. Running the full kit below at the same time takes 115 running watts (115W peak) → ~200W rated.

The list, with sourced watts

Appliance	Running watts	Starting (surge)
CPAP machine, device only — no humidifier (ResMed AirSense 10 class)	90	—
CPAP with heated humidifier (+ ClimateLineAir heated tube) — ResMed AirSense 10 class	90	—
Cell phone charger	25	—

The arithmetic, both ways

CPAP machine, device only — no humidifier (ResMed AirSense 10 class) alone: 90W running + 0W surge = 90W → × 1.2 = ~200W

Full kit (every item below, at once): 115W running + 0W largest surge = 115W → × 1.2 = ~200W

The arithmetic

Running total: 115W
+ largest single starting surge: 0W
= peak demand: 115W
× 1.2 headroom → recommended rating: ~200W

Generators that cover this (from our verified catalog)

Honda EU1000i
900W rated · 1,000W starting · gasoline · inverter
Spec: manufacturer_pdf

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Champion 201230 (2000W Dual Fuel Inverter, CO Shield)
1,700W rated · 2,000W starting · dual fuel (gasoline/propane) · inverter
Spec: manufacturer

As an Amazon Associate, needwatts.com earns from qualifying purchases. Links below are affiliate links — this never affects our wattage math or which units we list.

See Champion 201230 (2000W Dual Fuel Inverter, CO Shield) on Amazon →

WEN 56203i
1,700W rated · 2,000W starting · gasoline · inverter
Spec: manufacturer

As an Amazon Associate, needwatts.com earns from qualifying purchases. Links below are affiliate links — this never affects our wattage math or which units we list.

See WEN 56203i on Amazon →

Adjust this list in the calculator →

How many watts do I need for a cpap machine, device only — no humidifier?

90 running watts with 90W available at startup; ~200W rated recommended. The full kit on this page needs ~200W.

Why do starting watts matter?

Motor-driven appliances (fridges, pumps, AC compressors) briefly draw 2–4× their running watts at startup. A generator must cover running load plus the largest single surge, or the motor stalls and breakers trip.

Is a bigger generator always better?

No — oversized open-frame units burn more fuel and run louder. Size to your real list with ~20% headroom.

Sources

ResMed 'Power consumption of Air10 devices' (official measurement PDF) (manufacturer)
Lofta ResMed AirSense 10 90W AC power supply spec (vendor)
Wattage Worksheet '3R0WATTGUIDE' (generator reference guide, Home Depot-hosted PDF) (vendor)
A-iPower Wattage Chart (Sam's Club-hosted PDF) (vendor)

Figures are conservative sizing values chosen from the range these sources report. Your appliance's nameplate is authoritative.