A Power Station for a CPAP, Not for a Space Heater

If you use a CPAP, a portable power station is one of the best things you can bring camping. Just know what it can and can't do.

01How to size it

Power stations are rated in watt-hours (Wh). That's how much energy they hold.

Your CPAP draws some number of watts. Multiply by the hours you sleep:

Watts × hours = watt-hours needed

Many CPAP machines use roughly 30 to 60 watts without the heated humidifier and heated tube. With heat on, it can be several times that. Check your machine's manual or plug it into a watt meter at home for a real number.

Example

• 40 watts × 8 hours = 320 Wh
• Add about 15 to 20 percent for losses in the power station's inverter
• About 380 Wh per night

A 500 Wh power station: about one night. A 1,000 Wh unit: two nights, give or take.

02Getting more nights

• Turn off the heated humidifier and tube. This is the biggest saving. Many people are fine without it for a few nights; ask your doctor if you're unsure.
• Use a DC cable if your CPAP maker sells one. Running on 12V DC skips the inverter's losses.
• Recharge during the day from your car or solar.

03Why not a space heater?

A small electric space heater uses about 1,500 watts on high. A 1,000 Wh power station would last well under an hour. Even on low, it's gone fast. Power stations are for small loads all night, not heating.

For warmth, use a good sleeping bag and pad. See sleeping bag temperature ratings and tent heaters: what's safe.

04Other good uses

Phone and camera charging, lights, a small fan, a 12-volt fridge for a while. See portable power stations for camping.

05Test it at home

Run your CPAP off the power station for a full night at home before the trip. You'll know exactly what you have.

Related: Hot Tent Camping: Is a Wood Stove Tent Worth It? · How Long Will a Power Station Run a Camping Fridge?