How to Keep Your CPAP Running Through a Power Outage

An estimated 26% of adults aged 30 to 70 have obstructive sleep apnea, per the American Academy of Sleep Medicine — and for most of the people in that group, "the power's out" isn't a minor inconvenience, it's a night without a machine their sleep (and in some cases their airway) depends on. This page is the honest math on that one line item: what your specific CPAP model actually draws, the single change that roughly doubles your runtime, and how many outage-nights a given battery size really buys you.

What your CPAP actually draws

Spec sheets bury the number that matters — power consumption — inside a PDF nobody reads until the lights go out. Here's what the manufacturers themselves publish:

Two things jump out. First, a CPAP isn't a cycling load like a fridge — it runs close to its typical draw continuously for the whole time you're asleep, so there's no duty-cycle discount to apply the way there is for a compressor. Second, the humidifier is most of the bill: AirMini's humidifier-free 27W peak is roughly half of AirSense 10's 53W typical with heated water running. That gap is your biggest lever, and it costs nothing.

Turn the humidifier off before you turn anything else off

If you take one thing from this page: for an outage, run the humidifier dry or off entirely. It's not a marginal saving — it's close to half the machine's draw, because heating water pulls more power than moving air ever will. A dry night's sleep for a few days beats running out of battery at 3 a.m., and most machines let you disable heated humidification from the settings menu in seconds.

How many nights does a power station actually buy you

Take an 8-hour night, apply the standard 85% inverter haircut this site uses everywhere (see the full watt-hour calculator for why), and CPAP alone works out to:

• Humidifier on (53–56W typical): ~424–449Wh raw for the night → ~500–530Wh usable-needed
• Humidifier off (~27W): ~216Wh raw for the night → ~255Wh usable-needed

Against real unit capacities:

That's CPAP running alone — no fridge, no lights, nothing else drawing from the same battery. In a real outage it's sharing capacity with the rest of the household's essentials, which is exactly what the watt-hour calculator is built to budget across every appliance at once, CPAP included by default.

Dedicated CPAP battery, or just use your power station

The CPAP-specific battery market — Medistrom's Pilot-Flex is the popular one — sells convenience, not capacity. $349 buys 98Wh and roughly 1-2 nights on a single charge: light enough for a carry-on, useless for a multi-day outage on its own. A general power station in the 900Wh-plus class costs more up front but delivers several nights of CPAP by itself, plus everything else in the house that a 98Wh brick can't touch — the fridge, phones, a lamp. For travel or a campsite, the dedicated battery's weight and size win. For sitting in a closet waiting for the grid to go down, a general-purpose unit is the better dollar for the watt-hour, and it isn't a single-purpose device the other 364 nights a year.

If CPAP is the load that decides your purchase, size up rather than down — the home backup rankings are sorted by exactly the kind of real-world capacity math this page uses, and the hurricane prep guide covers what else to plan around a multi-day outage where CPAP is running every single night, not just one.