What size power station do I need for medical equipment?

It depends entirely on the device. A CPAP draws 30 to 100 watts and a 500 to 1,000Wh station covers a night. A refrigerator for medication draws 50 to 100 watts but cycles, so 1,000Wh covers a day or more. A home oxygen concentrator draws 300 to 600 watts continuously and needs 2,000Wh or more just to bridge a few hours. Match the battery to the device's real draw, and always use pure sine wave power.

Does medical equipment need pure sine wave power?

Yes. Devices with motors and control electronics — oxygen concentrators, CPAPs, medication refrigerators — should only run on pure sine wave power. Modified sine wave inverters, common in cheap generators under $300, can cause errors, overheating, or damage. Buy a power station with a true pure sine wave inverter for any medical device.

Is battery backup enough for life-support equipment?

For low-draw devices like a CPAP, a battery can fully cover the need. For high-draw continuous devices like a home oxygen concentrator, a battery is a bridge — hours, not days — and must be part of a larger plan that includes backup oxygen tanks, solar recharging, utility medical-needs registration, and a relocation option for long outages. Never rely on a battery alone for continuous life support.

backup power for medical equipment

Short answer

The right backup depends entirely on the device. A CPAP is easy — almost any pure-sine-wave station covers a night. A medication fridge is nearly as easy. A home oxygen concentrator is the hard case — it draws too much for a battery to cover for long, so battery backup there is a bridge inside a bigger plan. Below, the honest version for each device, and what to actually buy.

Most backup-power advice is written for convenience — keeping the lights and the fridge on. This guide is for the households where power is not a convenience: someone depends on a machine, and when the grid goes down, there is a clock running. I'll be straight about what a battery can do, where it can't, and how to size one for the device you actually have.

the rule that applies to every device

Before the device-by-device breakdown, two things are true for all medical equipment:

Pure sine wave only. Motors and control boards in medical devices need clean power. Cheap modified-sine-wave inverters (common under ~$300) can cause errors, overheating, or damage. Every recommendation here is pure sine wave.
Size to the real draw, then add margin. Find the device's wattage on its label, account for any startup surge on motorized equipment, and give yourself headroom. Under-buying is the mistake that leaves you stranded.

cpap — the easy one

A CPAP draws 30 to 60 watts without a humidifier, 80 to 120 watts with one. That's a low-power problem: a 500 to 1,000Wh station covers a full night, often two, and can run every night for years on LiFePO4 cells. If your dependency is a CPAP, backup power is genuinely solved with a modestly sized unit.

Full breakdown, runtime math, and picks: best solar generator for CPAP.

refrigerated medication — nearly as easy

Insulin, biologics, and other refrigerated medications fail if they get too warm, so a fridge is a real dependency. The good news: a small medication or mini fridge draws only 50 to 100 watts and cycles on and off, so a 1,000Wh station covers a day or more. The one catch is the compressor's startup surge — you want a unit with pure sine wave and enough surge headroom, which the picks below all have.

One honest nuance worth knowing: in-use insulin is usually fine at room temperature for a limited window, while your unopened stockpile is what truly needs to stay cold. Full details and picks: how to keep medication cold in an outage.

oxygen concentrator — the hard case

This is where honesty matters most. A portable pulse-dose concentrator (under ~100W) is easy to back up. But a home continuous-flow concentrator draws 300 to 600 watts non-stop — roughly 8,000+ watt-hours a day. No portable battery covers that for long. There, a power station is a bridge of hours, and it has to be one layer of a plan that also includes:

Backup oxygen cylinders from your supplier — your true fallback.
Solar panels to recharge the station during daylight and extend it across a multi-day outage.
Registering with your utility as a medical-needs customer for priority restoration.
A relocation plan for a long outage.

Runtime math, the pure-sine-wave requirement, and the units that actually fit: best power station for an oxygen concentrator.

how to size any device in 60 seconds

Read the wattage off the device label (or multiply amps × volts).
Multiply by the hours you need to cover. A 60W CPAP for 8 hours = 480Wh. A 350W concentrator for 8 hours = 2,800Wh.
Add ~20% headroom for inverter losses and cold-weather battery performance.
Check the surge if the device has a motor (fridge, concentrator) — the station's surge rating must clear the startup spike.
Confirm pure sine wave and, if you want seamless switchover, UPS mode with a fast transfer time.

Our power load calculator does this math for any device and tells you the battery size to buy.

the bottom line

For a CPAP or a medication fridge, a right-sized pure-sine-wave power station genuinely solves the problem. For continuous home oxygen, a battery is a bridge, not the whole answer — pair it with solar and keep your supplier's backup tanks. In every case: match the battery to the real draw, insist on pure sine wave, and buy it and test it before the outage, not during one.

Some links in these guides are affiliate links. We may earn a commission at no cost to you. This is general information, not medical advice — coordinate backup power planning for life-support equipment with your device supplier and physician. See our affiliate disclosure.

Frequently asked questions

What size power station do I need for medical equipment?: It depends entirely on the device. A CPAP draws 30 to 100 watts and a 500 to 1,000Wh station covers a night. A refrigerator for medication draws 50 to 100 watts but cycles, so 1,000Wh covers a day or more. A home oxygen concentrator draws 300 to 600 watts continuously and needs 2,000Wh or more just to bridge a few hours. Match the battery to the device's real draw, and always use pure sine wave power.
Does medical equipment need pure sine wave power?: Yes. Devices with motors and control electronics — oxygen concentrators, CPAPs, medication refrigerators — should only run on pure sine wave power. Modified sine wave inverters, common in cheap generators under $300, can cause errors, overheating, or damage. Buy a power station with a true pure sine wave inverter for any medical device.
Is battery backup enough for life-support equipment?: For low-draw devices like a CPAP, a battery can fully cover the need. For high-draw continuous devices like a home oxygen concentrator, a battery is a bridge — hours, not days — and must be part of a larger plan that includes backup oxygen tanks, solar recharging, utility medical-needs registration, and a relocation option for long outages. Never rely on a battery alone for continuous life support.