Power Outages and Medical Devices: How to Keep a CPAP, Oxygen Concentrator or Insulin Cold

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Quick answer: A CPAP with the humidifier on can burn close to 400 watt hours a night, so plan on roughly 1,200 Wh for three nights. A portable oxygen concentrator on pulse dose 2 needs far less, around 450 to 500 Wh a day, but a stationary 5 liter concentrator draws 340 watts continuously and can drain a 2,048 Wh power station in about six hours. Opened or unopened insulin is generally fine between 59°F and 86°F for up to 28 days, per the FDA, but it must never freeze.

Who a Multi Day Blackout Actually Threatens

A power outage is an inconvenience for most households and a medical emergency for a specific group of people, and that group is larger than most disaster guides admit. The American Lung Association and the CDC both flag the same four categories of at home electric medical equipment as the ones that turn a blackout into a 911 call: CPAP and BiPAP machines for obstructive sleep apnea, oxygen concentrators (both portable and stationary), suction machines and nebulizers for people who cannot clear their own airway, and insulin pumps for people with type 1 diabetes.

Layer on top of that a second group that never shows up on a “medical devices” checklist because the device is a refrigerator: anyone storing insulin, certain GLP-1 injectables, or other temperature sensitive biologics. The American Diabetes Association and the FDA both publish specific temperature windows for these drugs, and getting the number wrong either wastes an expensive prescription or means injecting a drug that has partially broken down.

None of this is theoretical. The American Academy of Sleep Medicine has told patients for years to have a plan with their sleep provider for untreated apnea, because it raises the risk of dangerous overnight oxygen drops, not just daytime grogginess. If you are newly diagnosed and still working out insurance coverage for your first machine, our breakdown of the proposed CMS billing rule for home sleep tests explains why that paperwork keeps changing. If you also travel with your machine, the same power math applies on the road; see our guide to traveling with a CPAP for a packing list that assumes no wall outlet.

How Long Insulin Survives Without a Fridge, According to the FDA

Most insulin, whether the vial or pen has been opened or is still sealed, tolerates a temperature between 59°F and 86°F for up to 28 days, according to FDA guidance on emergency insulin storage. That is the number to memorize, because it means a short blackout is almost never a crisis if your house stays below 86°F.

Below that threshold, refrigerated storage between 36°F and 46°F keeps insulin viable all the way to its printed expiration date. Above 86°F, insulin does not become instantly dangerous, but it degrades the longer it sits in the heat, and the FDA is explicit that once you regain access to properly refrigerated insulin, discard anything that spent extended time above that line. Insulin pump infusion sets carry a tighter rule: discard and replace after 48 hours, or immediately if exposed to anything above 98.6°F.

Two rules matter more than any Wh calculation in this section. First, never let insulin freeze; a cooler packed with ice can drop below freezing if the vial sits directly against the ice, so wrap it in a towel or keep it in a sealed bag one layer removed from direct ice contact. Second, insulin held in a cooler with ice typically holds refrigerator range for 24 to 48 hours before the ice needs replacing, so plan your ice runs before the first batch melts, not after. If you are ever unsure whether a specific product tolerates room temperature differently than these general FDA numbers, the manufacturer lines are staffed for exactly this question: Lilly at 1-800-545-5979, Sanofi at 1-800-633-1610, and Novo Nordisk at 1-800-727-6500.

How Many Watts Your CPAP Actually Pulls (The Humidifier Changes Everything)

This is the number most backup power articles get wrong, because they quote the machine’s power supply rating instead of what it actually draws. The ResMed AirSense 11, the most common machine sold in the US right now, ships with a 65W power supply, but that is a ceiling, not a typical draw.

• Humidifier off, low pressure (4 to 8 cmH2O): 5 to 18 watts
• Humidifier off, moderate pressure (9 to 15 cmH2O): 18 to 35 watts
• HumidAir humidifier on, level 1 to 2, no heated hose: 35 to 50 watts
• HumidAir on level 3 to 4 with the ClimateLine Max heated hose: 50 to 72 watts at peak

A real overnight test cited by CPAP power specialists at MedicSolar, running AutoSet at pressure 12 with the humidifier on level 2 and heated hose off, used 380 Wh across an 8.97 hour night. That is the single most useful number in this article: a humidified CPAP night costs roughly 380 to 420 Wh once you account for a small conversion loss through the battery’s inverter. Skip the humidifier and that number drops to 150 to 280 Wh, since you spend most of the night in the 18 to 35 watt band instead of the 35 to 72 watt band.

Running an older AirSense 10? Budget higher. That model ships with a 90W supply and runs hotter across every setting than the 11, so add 15 to 20 percent to every number above if you have not upgraded.

How Many Watts an Oxygen Concentrator Pulls (Portable and Stationary Are Different Universes)

This is where the math splits hard, and it is the single biggest mistake people make when they buy a power station based on a CPAP calculation and assume it will also cover their oxygen. Portable pulse dose concentrators sip power. The Inogen One G5, one of the most efficient units sold, draws roughly 18.7 watts on pulse setting 2, according to comparison data from oxygen equipment retailers. Across the category, portable pulse dose units generally run 40 to 130 watts depending on flow setting, with a rough average near 128 watts on less efficient models.

Stationary continuous flow concentrators are an entirely different load. A 5 liter unit like the Invacare Perfecto2 draws about 340 watts continuously, running around the clock, not just at night. A 2,048 Wh power station, fully charged, gives you barely over 6 hours of runtime (2,048 Wh divided by 340 W equals roughly 6.0 hours) before it is empty. That is not a backup plan for a multi day outage. It is a bridge to the next charge, a generator, or a supply of backup oxygen tanks that need no electricity at all.

If you rely on a stationary concentrator, talk to your durable medical equipment supplier now, before the next outage, about a standby E cylinder or M6 tank on hand at home. The American Lung Association and CDC both list this as a standard part of an oxygen user’s emergency plan, precisely because battery power stations were never designed to carry a 24/7, 340 watt continuous load for days at a time.

The Math: How Many Watt Hours You Actually Need

Use this formula for any device: Wh needed = average watts x hours of use x 1.15 (the 1.15 accounts for typical inverter conversion loss when you pull AC power out of a battery).

Two takeaways from that table. A single mid-size power station in the 1,000 to 1,100 Wh class comfortably covers one humidified CPAP night with plenty of margin left for a phone and a CPAP wipes light. Stack a portable oxygen concentrator on the same battery overnight and you are close to the battery’s full capacity by morning, so if you run both devices from one unit, size up to the 2,000 Wh class or plan to recharge from a car or generator during the day.

Four Power Stations That Actually Cover This Math

All four use lithium iron phosphate (LiFePO4) cells and pure sine wave inverters, which matters for medical electronics: a modified sine wave inverter can introduce electrical noise that some CPAP motors and oxygen concentrator compressors tolerate poorly, so pure sine wave is the one spec you should never compromise on here.

If your household only needs one CPAP covered with the humidifier running, the Jackery or the Anker gives you headroom for a second bad night before you find an outlet. If you are also charging a portable oxygen concentrator, running a mini fridge for insulin, or riding out a multi day outage with no generator, the Eco-Worthy PS2400 is the one built for that math, since its 2,048 Wh roughly doubles the other three for the same CPAP load.

Who Should Not Try to Run This on a Power Station Alone

Be honest about one category: if you or a family member depends on a stationary, continuous flow oxygen concentrator, a portable power station is a stopgap measured in hours, not a solution measured in days. That 340 watt continuous draw outpaces what a consumer battery in this price range can sustain. That household needs three things in place before the next storm watch, not during it: a standing order for backup E or M6 oxygen tanks from your DME supplier, a documented plan with your prescribing physician for concentrator downtime, and enrollment in your electric utility’s medical priority or “medical baseline” program, which most major US utilities offer and which can mean earlier restoration for registered life support accounts.

Safety Rules That Are Not Optional

• Never run a gasoline or propane generator inside a home, garage, breezeway, or within 20 feet of a window, door, or vent. The CDC is explicit on this distance because carbon monoxide from generator exhaust is odorless and has killed people who thought an open garage door was enough ventilation.
• Size your generator or battery for the startup surge, not just the running watts. Oxygen concentrator compressors and some CPAP heater plates pull a short spike well above their steady state wattage when they switch on; the peak/surge rating on a power station (not the continuous rating) is what has to cover that moment.
• Talk to your prescribing physician about a documented backup plan for oxygen specifically, before an outage, not during one. Ask what symptoms mean you need to call for help immediately if your flow rate drops or stops.
• Register with your electric utility as a medical equipment household. Programs go by different names (medical baseline, critical care, life support registry) but the effect is similar: your address gets flagged for priority restoration and, in many territories, advance notice before planned outages.

Your Prep Checklist for Today

1. Weigh your own CPAP setup: check your humidifier level and hose type, then use the Wh table above to find your real overnight number, not the machine’s power supply rating.
2. Call your electric utility and ask specifically for their “medical baseline,” “critical care,” or “life support” customer registration program, and get your account flagged this week.
3. Call your DME or oxygen supplier and confirm, in writing if possible, that you have a standing backup tank order if you use a stationary concentrator.
4. Buy a hard sided cooler and two reusable ice packs sized for your specific insulin vials or pens, and keep them stored empty and ready, not packed away in a closet.
5. Pick one power station sized to your real Wh math from the table above and fully charge it once a month; LiFePO4 batteries hold charge for months but a dead battery on the night you need it defeats the purpose.
6. Write your insulin manufacturer’s emergency line on a card in your go bag: Lilly 1-800-545-5979, Sanofi 1-800-633-1610, Novo Nordisk 1-800-727-6500.
7. If you travel regularly with a CPAP, apply the same Wh math to a smaller travel battery; our CPAP travel guide covers TSA rules and battery size for flights specifically.

Frequently Asked Questions

How long will my CPAP run on a portable power station during a blackout?

With the humidifier on at a moderate level, plan on roughly 400 Wh per 8 hour night, which means a 1,000 to 1,070 Wh power station covers about two nights before it needs a recharge from a wall outlet, car, or solar panel. Turn the humidifier off and that same battery can stretch closer to four or five nights.

Can I run a stationary oxygen concentrator on a battery power station?

Only briefly. A 5 liter stationary concentrator draws about 340 watts continuously, which drains even a large 2,048 Wh power station in around 6 hours. Stationary concentrator users need backup oxygen tanks and a utility medical priority registration, not just a bigger battery.

How long is insulin good without refrigeration?

According to FDA guidance, most insulin in vials, cartridges, or pens, whether opened or still sealed, tolerates 59°F to 86°F for up to 28 days. It must never be allowed to freeze, and once it has been above 86°F for an extended period, replace it as soon as refrigerated insulin is available again.

Is it safe to run a gas generator to power medical equipment?

Only outdoors, at least 20 feet from any window, door, or vent, per CDC carbon monoxide guidance. Never run a generator in a garage even with the door open, and never run one indoors under any circumstances.

Do I need a pure sine wave inverter for my CPAP or oxygen concentrator?

Yes. A modified sine wave inverter can introduce electrical noise that some CPAP motors and oxygen concentrator compressors handle poorly, sometimes causing error codes or reduced motor life. All four power stations compared above use pure sine wave inverters for that reason.

Should I sign up for my utility’s medical priority program before an outage happens?

Yes, and do it now rather than waiting for a storm warning. Most major US electric utilities run some version of a medical baseline, critical care, or life support registry that flags your address for priority restoration and, in many cases, advance notice before planned outages.

This article is for general informational purposes and does not replace personalized medical advice. Talk with your physician, sleep specialist, or durable medical equipment supplier before changing how you store insulin, operate a CPAP, or manage oxygen therapy during a power outage.