CPAP backup calculator

Estimate how many nights a power station can run a CPAP.

Use your machine's documented or measured watts, any added heated-accessory load, battery size, usable capacity, and sleep schedule to estimate backup coverage.

Estimated coverage1.3 nights

This setup is short of your 2 night target.

Inputs

Machine and battery

Base CPAP watts with heat offUse a meter or manufacturer power specs when possible.Added humidifier/heated tube wattsEnter a measured or manufacturer-documented increase. Leave at 0 rather than guessing.Power station capacityUse listed watt-hours. For 12V batteries, convert first with the amp hours to watt hours calculator.Usable battery percentAccounts for inverter losses, reserve, and real-world headroom.Hours per nightUse your usual sleep window plus a little margin.Nights neededUsed to estimate the battery class you should compare.

Inputs valid. Estimate updated.

CPAP energy varies by machine, pressure, mask leak, humidifier, heated tube, altitude, and connection method. Manufacturer battery guides, such as ResMed's battery guide, are a better source than a generic preset.

Important CPAP note

This is a sizing estimate, not medical advice. If CPAP backup is medically critical, confirm the backup plan with your equipment provider or clinician and check your exact machine's power requirements.

CPAP backup guides

Use the estimate before picking a size class

Guide

Power station size for CPAP

See what to check before choosing a CPAP backup battery.

Read guide

Overnight

Can a power station run a CPAP overnight?

Understand the settings that change one-night runtime.

Read guide

Recharge

Solar recharge time calculator

Check whether a panel can refill the station before the next night.

Open calculator