Best Solar Generator for a CPAP Machine

It is not the fridge that keeps you awake in a storm. It is knowing that when the wind takes the line down, you are not sleeping, and tomorrow is going to be rough.

Here is the good news, and it is genuinely good. This is the cheapest backup power problem there is.

Most people shopping for a CPAP battery get talked into three times what they need.

The one setting that halves your cost

Turn off the heated humidifier.

That's it. That's the whole trick.

A CPAP motor sips power — around 40 watts. verify The heater that warms the water is what doubles it, and it's the least essential part of the machine.

Over eight hours: about 300 watt-hours without the humidifier, closer to 700 with it. verify

Use the heated hose setting sparingly too — it's the same problem in a different place.

Use the DC cable if you have one

Most CPAP machines ship with, or offer, a 12V DC cable.

Your battery stores DC. The AC outlet converts it to AC, and then your CPAP's brick converts it straight back to DC. You lose energy at both ends for no reason.

Plug into the battery's 12V port instead and you get meaningfully more hours out of the same pack. verify Check your machine's manual for the right cable — do not improvise one.

What we'd actually buy

For one night, cheaply: Anker SOLIX C300

288Wh. That covers a humidifier-off CPAP for a night with a little margin. verify

It's light, it's quiet, and it costs a fraction of what people get sold for this job. Three USB-C ports means your phone charges off the same box without another brick.

Who it's wrong for: anyone who wants the humidifier on, or who also wants to keep a fridge running. It cannot do either. If your outage worry is bigger than "I need to sleep," buy bigger.

If you want the humidifier on: step up to roughly 700–1,000Wh

This is the size bracket rather than a single pick, because the humidifier is what decides it.

With the heated humidifier running, draw can roughly triple. verify A 288Wh unit that comfortably covers a dry-air night will not get you to morning with the humidifier on, and finding that out at 3am is the wrong time.

Around 700Wh covers a humidified night with margin. Around 1,000Wh covers it and leaves room for phones, a lamp and the router — which is why most people who start here end up buying the 1kWh unit below anyway.

What to check before buying: your machine's actual draw with your settings, from its manual or a plug-in meter. CPAP consumption varies more between machines and pressure settings than any table can capture.

If you also want your food to survive: EcoFlow DELTA 2

Once you're protecting the fridge as well as the CPAP, you're in a different size class.

1,024Wh runs the CPAP all night and still has plenty left for the fridge, the modem and phones. verify It refills from a wall outlet fast, which matters if power flickers back mid-outage.

Who it's wrong for: somebody who genuinely only needs the CPAP. You'd be buying triple what the job requires.

What not to buy

Don't buy a "CPAP battery" from a medical supply company. They're often priced far above a general-purpose power station with the same or less capacity, and they do nothing else. A standard power station runs your CPAP and your phone and your lamp.

Don't buy a lead-acid jump starter for this. They're heavy, they hold much less usable energy than the label implies, and they hate being deeply discharged. They also die after a couple of years of sitting.

Don't buy a 100Wh power bank. It will not make it through a night, and finding that out at 3am is a bad way to find out.

Two nights or more

One night is easy. Three nights is a different question.

At that point you need a way to put energy back in: a solar panel, or a 12V adapter that charges from your car. The car option is unglamorous and it works — your car is already in the driveway, and idling it for half an hour puts a real dent in the problem.

The straight answer

Turn the humidifier off, use the DC cable, and buy something in the 300-500Wh range.

That solves the problem for most people, for less money than nearly every article on this subject will tell you. Spend the difference on a solar panel if your outages run long, or don't spend it at all.