What Size Generator Do I Need to Run a CPAP?

No surge is listed for a CPAP, so this page does not invent one.

Quick answer: Champion lists a CPAP at 30–60 watts and a heated CPAP at 60–120 watts, and it does not list a starting surge. Plan on a running rating that clears 120 W and do not add a surge the chart does not show. A Honda EU2200i is rated 1,800 W with a 2,200 W maximum and is listed at 48–57 dB(A), so the watts fit and the spec sheet is the quiet-inverter reference.

Affiliate

Affiliate disclosure: as an Amazon Associate, we earn from qualifying purchases — at no cost to you.

Shop generators this size on Amazon

Running and starting watts

Load	Running watts	Starting watts	Source
CPAP	30–60	Not listed	Champion
CPAP, heated	60–120	Not listed	Champion

Honda's wattage guide lists starting watts, then running watts. Champion's chart lists running watts, then starting watts. This table puts every figure in the Running and Starting columns. Not listed means that source does not give a separate starting figure.

How to size it

Add the running watts of every load that will be on together, then add the single highest starting surge (Generac; Honda). Generac notes that starting watts are often 2–3 times running watts, and that standby units should get a dealer survey.

The EU2200i spec sheet also lists 47.4 lb, 3.2 hours at rated load, and 8.1 hours at 1/4 load. A CPAP at 30–60 W, or 60–120 W heated, is under the 1,800 W rated output, so this page does not invent a longer runtime than those published hours. Honda notes that an inverter converts AC to DC and back to AC, which gives lower THD than a conventional generator that runs at full RPM. The machine still stays outdoors.

Check a full load list on the generator size calculator.

Affiliate

Shop generators this size on Amazon Heavy-duty generator extension cords on Amazon

Run the generator outdoors only, 20 ft from the house (CPSC).

FAQ

Does a CPAP have a starting surge?

Champion does not list one. The rows are 30–60 W and 60–120 W heated. Do not multiply them.

Why mention the EU2200i?

The watts are small. The EU2200i is the quiet inverter in the source list: 48–57 dB(A), 1,800 W rated, 2,200 W maximum, 47.4 lb.

How long does that spec sheet say it runs?

Honda lists 3.2 hours at rated load and 8.1 hours at 1/4 load. Those are the published runtimes, not a CPAP-only estimate.

Can the CPAP sit next to the generator?

No. CPSC says to run a generator outdoors only, 20 ft from the house. Use an outdoor-rated cord to reach the machine.