Free Preparedness Tool

CPAP Battery Backup Calculator

CPAP machine on a nightstand connected to a portable battery power station with green indicator lights, storm visible through dark window

Power is out. How long will your CPAP battery last — and what size do you need for 3, 7, or 14 nights? Enter your machine settings and get your answer.

Enter Your CPAP Setup

Select your machine type and settings. We'll calculate what battery size you need to get through each night — and how many nights a given battery will last.

Check your prescription or machine display. If unsure, enter 10 — a common midrange setting.
Your CPAP Battery Requirements

Recommendations:

    Planning estimate only. Actual power consumption varies by machine model, mask type, pressure fluctuations, altitude, and humidifier settings. These calculations are estimates based on typical wattage ranges for each machine class. Consult your CPAP equipment supplier or respiratory therapist for precise specifications for your machine. Always test your battery system before an actual emergency.

    Common Questions

    What happens if I skip CPAP during a power outage?
    For most people with sleep apnea, one or two nights without CPAP causes disrupted sleep and increased apnea events, leading to fatigue and elevated blood pressure the next day. For people with severe sleep apnea or related cardiovascular conditions, extended periods without therapy can increase risk of cardiac arrhythmia or other events. Talk to your doctor about your specific risk level.
    Can I use my car battery to run my CPAP?
    Yes, with the right equipment. Most CPAP machines can run from a 12V DC car adapter (check your machine's specifications). A dedicated portable power station (like a Jackery or Goal Zero) is safer and more reliable than running directly from your car battery. Running a car continuously to power a CPAP is dangerous due to carbon monoxide risk — never run your car in a garage.
    What size battery bank do I need for my CPAP?
    A basic CPAP without humidifier at mid-range pressure uses approximately 30–45 watts per hour. For 8 hours of use, that is 240–360 watt-hours. A 288Wh battery (such as the Jackery 300 or similar) provides approximately one night. For multiple nights, look at 500–1000Wh portable power stations. With humidifier, double these figures.
    Does Medicare cover CPAP battery backup?
    Medicare Part B covers CPAP machines and supplies as durable medical equipment. Coverage for battery backup systems varies — some portable power stations used for CPAP are covered under certain circumstances. Contact your Medicare plan and CPAP supplier for specifics. Your physician may need to document medical necessity for battery backup coverage.
    Planning Estimate Only: Actual power consumption varies by machine model, mask type, pressure fluctuations, altitude, and humidifier settings. These calculations are estimates based on typical wattage ranges for each machine class. Consult your CPAP equipment supplier or respiratory therapist for specifications for your machine. Always test your battery system before an actual emergency. This does not constitute medical or equipment advice. In any emergency, follow official guidance from FEMA Ready.gov and your local emergency management authority. Franklyns Bay LLC assumes no liability for decisions made based on this tool. Full disclaimer →