Will a normal home inverter run my CPAP all night?

Almost certainly yes. At around 50 watts with the humidifier off, a CPAP uses a small share of a typical 150 Ah inverter battery over eight hours.

Is it safe to run a CPAP on an inverter?

Yes. Pure sine wave is preferable, and most machines tolerate modified sine wave. Check your machine's manual if you are unsure about your specific inverter.

Does a sudden power cut harm the machine or lose my data?

No. The machine shuts down, then restarts with your settings and therapy history intact when power returns. A surge protector is still worth having.

Running a CPAP through a Kerala power cut: inverter, UPS and battery

Last updated: 2026-10-28

Quick answer

A CPAP draws roughly 30 to 50 watts with the humidifier off, and can peak near 100 watts with the heated humidifier and heated tube running — about the same as a ceiling fan versus a small iron. Any normal home inverter will run one, and a pure sine wave inverter is preferable because of the machine's switching power supply. The single most useful trick is turning the humidifier off when you are on backup power: it cuts consumption by more than half and costs you nothing but a slightly drier nose.

What a CPAP actually consumes

The blower itself is modest. At typical therapy pressures a ResMed AirSense draws in the region of 30 to 50 watts. Over eight hours that is roughly 0.3 to 0.4 units of electricity a night — a few hundred rupees a year, which surprises people who assume a medical device must be expensive to run.

The heated humidifier and the heated tube are the real load. They are resistive heaters, and with both on, peak draw climbs toward 100 watts. Every backup calculation you make should start by deciding whether the humidifier stays on.

Will a home inverter run it?

Yes, comfortably. A standard 600 to 900 VA home inverter with a 150 Ah battery stores far more energy than a CPAP needs for a night — the machine at 50 watts for eight hours is about 400 watt-hours, a small fraction of what that battery holds, even shared with a couple of fans and lights.

Two practical points. Prefer a pure sine wave inverter: CPAP power supplies work on modified sine wave in most cases, but pure sine is what manufacturers assume and it avoids a faint buzz some people hear. And make sure the bedroom plug point is actually on the inverter circuit, which in many Kerala houses it is not — the inverter feeds lights and fans but not the socket behind the bed.

What happens if the power goes and there is no backup

The machine stops, pressure falls, and most people wake within a minute or two because the mask becomes a closed mask you are breathing through. There is no danger — every CPAP mask has anti-asphyxia venting so you can breathe room air through it — but the therapy stops for the rest of the cut, and a long monsoon outage can cost you most of a night.

An outage does not damage the machine either. Power returns, the machine restarts, your settings and data are intact. If surges are common where you live, a simple surge protector on the plug is worth more than anything else you can buy.

Batteries, UPS and travel options

A computer UPS is a poor fit: it is sized for a few minutes of runtime and its square-wave output is not what you want all night. A small lithium power station rated 300 watt-hours and up will run a CPAP for a night with the humidifier off, and is the sensible option for travel, Sabarimala season, hospital stays and houses without an inverter. ResMed also sells DC converters for its machines, which avoid the loss of running an inverter.

Whatever you use, test it before you need it: run the machine on backup for a full night once, with the humidifier off, and see what the battery looks like in the morning.

What we set up

At delivery we tell you the machine's draw, show you how to switch the humidifier off from the menu in two taps, and check that your bedside socket is on the inverter if you have one. In districts where our technicians visit, that is part of the setup visit rather than a phone instruction.

If you are still deciding which machine to buy, compare the four — all of them run happily on an inverter, and the AirSense 11's humidifier is the most efficient of the group.

Running a CPAP through a Kerala power cut: inverter, UPS and battery

What a CPAP actually consumes

Will a home inverter run it?

What happens if the power goes and there is no backup

Batteries, UPS and travel options

What we set up

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