Using CPAP
CPAP Without Wall Power: Batteries, Camping and Power Outages
A power cut or a weekend in a tent does not have to mean a night without therapy. With some planning, most CPAP machines can run from batteries or DC power. Here is how to estimate what you need and stay safe.
Know how much power your machine uses
CPAP power use depends on the model, your pressure, and especially whether the humidifier and heated tubing are on. Heating water and tubing uses far more energy than the blower. Your manual or manufacturer's website usually lists typical power use, and many manufacturers publish battery run-time estimates for their own batteries.
Battery capacity is measured in watt-hours (Wh). A rough guide is: hours of run time is about the battery's usable watt-hours divided by your machine's average watts, minus some loss for conversion. Test your setup at home for a full night before you rely on it.
Ways to stretch battery life
- Turn off the humidifier and heated tubing. This is the single biggest saving. Some people use a heat and moisture exchanger (HME) attachment, if compatible with their mask and machine, to add a little moisture without power.
- Use a DC power cord or converter made for your machine rather than plugging the AC power supply into an inverter. Converting DC to AC and back wastes energy.
- Keep batteries charged and stored at moderate temperatures. Cold reduces capacity.
Battery options
Choices include batteries made by your CPAP manufacturer, general portable power stations, and deep-cycle batteries with an appropriate DC cable. Manufacturer batteries are designed for your machine. Whatever you use, check that it can supply the voltage and current your machine needs. If you plan to fly with a battery, check the FAA watt-hour limits.
Planning for power outages
- Keep a charged battery or power station ready, and recharge it after use.
- Some utilities have medical equipment registration programs that may prioritise notification or restoration. Ask your utility.
- Ask your DME what they recommend for your model.
- If you use a generator, never run it indoors, in a garage, or near windows. Generators produce carbon monoxide, which can be deadly. Use a carbon monoxide alarm at home.
If you cannot use CPAP for a night
Missing a night is not ideal, but for most adults with obstructive sleep apnea it is not an emergency. Try sleeping on your side or with your head elevated, avoid alcohol and sedating medicines, and get back on CPAP as soon as power returns. If you have a condition where your clinician has told you that you depend on the device (for example some people on bilevel with a backup rate or ventilators), you need a firmer backup plan, so discuss it with them now.
Frequently asked questions
How long will a battery run my CPAP?
It depends on the battery's watt-hours, your machine, your pressure and whether humidification is on. Divide usable watt-hours by your average watts for a rough estimate, and test it at home.
Can I use a car battery for CPAP?
Some people do with the correct DC cable, but avoid draining your vehicle's starting battery. A separate deep-cycle battery or portable power station is safer.
Is it dangerous to skip CPAP during a power outage?
For most people, one night without CPAP is not an emergency, though sleep will be worse. If you depend on your device for breathing support, plan backup power with your clinician.
Sources
This page is general information, not a diagnosis or medical advice. Read our medical disclaimer.