Portable Power Station for CPAP

My Patriot Supply says the Grid Doctor 300 can run a CPAP machine for up to about 8 hours. Your own result depends on your machine's rated watts, so read its label, apply hours = Wh x 0.85 / watts, and talk with your clinician about an outage plan for any medical device.

Disclosure: If you order through a My Patriot Supply link on this page, this site earns a commission. Your price stays the same. How we are paid.

Find your CPAP's watts

Start with the machine itself. Look for the rating on its label, on the power adapter or in the manual. It may be printed in watts, or as volts and amps, in which case multiply them: 1 amp at 12 volts is 12 watts, and 2 amps at 120 volts is 240 watts. Use the figure for the way you actually use the machine.

Several settings change the draw:

• A heated humidifier adds draw, often more than the blower itself.
• A heated hose adds more.
• Pressure setting and mask leak can change what the blower uses.
• DC cords. Some machines have a DC option that avoids an AC-to-DC conversion. Check your manual before using one, and use only the cable your manufacturer approves.

We do not publish a typical CPAP wattage as fact, because we found no source we could cite. The figures below are labelled assumptions for arithmetic only.

Runtime formula and worked example

The formula, using our planning assumption for conversion losses, is:

hours = Wh x 0.85 / watts

The 0.85 is our own allowance, not a seller figure. Without it you get the ideal ceiling, Wh / watts.

The Grid Doctor 300 holds 320Wh, per the seller, so 320 x 0.85 = 272Wh usable on our math. The Grid Doctor 3300 holds 2,048Wh, so 1,740.8Wh usable.

Example: 272 / 40 = 6.8 hours. The 40W row is the figure in our data file for a CPAP without a humidifier; the 60, 90 and 120W rows are further assumptions to show how the result falls as the draw rises. These are estimates from assumed watts, not seller figures. Data read on 2026-11-04.

The practical reading is a sleeping night. If your machine draws 40W and you sleep 8 hours, you need 40 x 8 = 320Wh before any loss, which is the 300's entire capacity. With losses, 6.8 hours is short of a full night. The 3300 covers several nights at 40W by the same arithmetic, though it is a far larger and heavier unit at 57.2 lb against 8.625 lb for the 300, per the seller.

The seller's 8-hour figure

My Patriot Supply's page for the Grid Doctor 300 lists its runtimes: a CPAP machine for up to 8 hours, a router for up to 16 hours, a mini refrigerator for up to 4 running hours and a 42-inch LED TV for up to 4 hours. The page does not say what CPAP wattage it assumes. Our ideal ceiling for a 40W machine is 320 / 40 = 8.0 hours, which matches the seller's number exactly. That suggests the seller's figure assumes about 40W and no losses. If so, "up to" is the right wording, and a humidifier or heated hose would shorten it. This is our inference, not something the page states.

We did not test the unit with a CPAP, and we have not seen an independent test. The seller's page also lists a pass-through charging feature for the 300, and it lists no UPS claim for it. Check the seller's page for how the unit behaves when mains power is restored. If your machine has to stay on without interruption, ask the seller and your device maker before relying on the unit.

Check with your clinician and plan a backup

A battery estimate is a sizing aid, not medical advice. Ready.gov's power outage guidance tells people who use electrically powered medical devices to talk with their medical provider about a power outage plan. Do that before an outage. Ask:

1. How many hours, if any, can I go without the machine, and what do I do if I must?
2. Does my machine have a manufacturer-approved battery or DC option?
3. Which of my settings, such as the humidifier, can I turn off to extend runtime?

Then build the plan in writing:

• Note the machine's rated watts and your pressure and humidifier settings.
• Compute runtime with the formula, using the lower number.
• Keep the power station charged. The seller's care note says to store the unit at 60% charge or more and recharge it every 3 months, and to avoid temperatures above 113 F.
• Charge your phone and a flashlight from the same unit, but count their watts in the total.
• Know where your fallback is, whether that is a larger battery, a vehicle with an approved adapter or a clinic.

Longer outages are a sizing question, and the power outage guide covers several-day plans. Battery wear is covered in how long power stations last, and the LiFePO4 guide covers the chemistry the seller says both units use. If you have read about the seller's EMP feature and want to see what the marketing language does and does not mean, see the seller's EMP claim and what it covers. Do not plug a power station into a wall outlet to power the house: plug the CPAP into the station's own outlet.

For the units themselves, see the Grid Doctor 300 review and the Grid Doctor 3300 review. The wider guide is the best portable power station for home backup.

FAQ

How long will a power station run my CPAP?

Divide usable watt-hours by your machine's watts. Our planning formula is hours = Wh x 0.85 / watts. At an assumed 40W, a 320Wh unit gives about 6.8 hours and a 2,048Wh unit about 43.5 hours. Use your machine's real rating.

Does a humidifier change the runtime?

Yes. The humidifier, and especially a heated one with a heated hose, raises the draw, so the same battery lasts fewer hours. Check your manual for the machine's rated watts with those features on.

Is the Grid Doctor 300's 8-hour figure reliable?

It is the seller's "up to" claim, and we did not test it. It equals 320Wh at a 40W draw with no losses, so a machine drawing more, or any real losses, will lower it.

Should I rely on a power station for my medical device?

Make that decision with your clinician. Ready.gov advises talking to your medical provider about an outage plan for electrically powered medical devices. A power station is one possible part of that plan.

Sources

• Power outages, Ready.gov, read 2026-11-04
• Grid Doctor 300 product page, My Patriot Supply: https://www.mypatriotsupply.com/products/solar-generator-300w-by-grid-doctor, read 2026-11-04
• Grid Doctor 3300 product page, My Patriot Supply: https://www.mypatriotsupply.com/products/grid-doctor-3300-emp-solar-generator, read 2026-11-04

Update history