What Can a Portable Power Station Actually Run? Fridge, Furnace, CPAP, Well Pump

Here is the straight answer before the math. A mid-size portable power station (around 1,000 watt-hours) will run a refrigerator for most of a day, a CPAP for several nights, your phones, lights, and internet for days, and a TV for a full evening.

It will not run your central air conditioner, and a space heater will flatten it in about half an hour. A hardwired furnace needs an electrician to wire in a transfer switch first. A 240-volt well pump needs a 240-volt unit, which a standard 1,000Wh station is not.

The difference between “this saved our food” and “this tripped off in ten seconds” comes down to two numbers on the spec sheet, and you can check both in the store aisle.

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The two numbers that decide everything

Every appliance question below comes back to the same pair of specs, so let’s name them once.

Output watts decide what the station can run at all. If your appliance draws more watts than the station can put out, it will not run, full stop, no matter how big the battery is. Motors and compressors complicate this with a startup surge, a one-second spike that can be five to ten times the running draw.

Watt-hours (Wh) decide how long it runs. A 1,024Wh battery feeding a 100-watt load runs roughly ten hours, minus a slice for the inverter (the electronics that convert battery power to household power eat some of it, so plan on about 85 percent of the rated capacity doing real work).

That is genuinely the whole framework. We keep a full device wattage table and sizing walkthrough in a separate guide. This page applies that framework to the specific appliances people actually worry about.

Can a power station run a refrigerator, and for how long?

Yes, this is the single most common reason people buy one, and it works well if the output is high enough. A typical fridge draws only 100 to 200 watts while the compressor runs, but it spikes to 600 to 1,200 watts for a moment when the compressor kicks on. That surge is the trap. A small 300-watt unit will trip on it even with a full battery. For a refrigerator, you want at least 1,000 watts of continuous output and a surge rating of 1,500 watts or more. The 1,800-watt units below clear both.

Runtime is friendlier than people expect, because a fridge compressor only cycles part-time. Most fridges use roughly 1 to 2 kilowatt-hours over a full day. So a unit in the 1,000Wh class keeps a fridge cold for most of a day if you are disciplined about door openings, and a 2,000Wh unit stretches toward two days.

If the refrigerator is your whole reason for buying, we walk through the door-discipline tricks and cooler-transfer strategy in how to keep a fridge running during an outage.

Can it run a furnace in winter?

This is the question with the asterisk. The load itself is manageable: a gas furnace does not make heat with electricity, it only needs power for the blower fan, the igniter, and the controls. Most gas furnace blowers draw somewhere in the few-hundred-watt range while running, with a start surge on top, well within reach of any 1,800-watt unit.

The catch is the plug, or rather the lack of one. Furnaces are hardwired into the house, so there is nothing to plug into the power station. The clean solution is having an electrician install a transfer switch or an interlock so the furnace circuit can be fed from backup power. That is a real project with real cost, but it converts a battery from “phones and fridge” into “the heat stays on,” which in a northern winter is the whole game.

An electric furnace or heat pump strip heat is a different story entirely. Those draw thousands of watts continuously and are not realistic battery loads.

Will it run a CPAP overnight? (yes, easily)

This is the load portable batteries are best at. A CPAP without the heated humidifier draws only 30 to 60 watts. Across an eight-hour night that is roughly 240 to 480 watt-hours, which means a compact 512Wh unit covers a full night for most machines (a power-hungry one at the top of that range will run it close, so know your machine’s draw), and a 1,000Wh unit covers two or more.

The one setting that changes the math is the heated humidifier and heated tube, which multiply the draw. If you depend on humidification, either budget a bigger battery or run the humidifier passively (most machines work without heat, the air is just drier). If CPAP backup is your main reason for buying, our power stations for CPAP picks are sized for exactly this.

Can it run a well pump or sump pump?

Here is where you have to read the fine print, because the two pumps behave very differently.

Sump pumps are usually 120-volt plug-in motors, so they are at least pluggable. The problem is surge. A pump that draws several hundred watts running can spike to two or three times that at startup, and it starts every time the pit fills. You want a station with a high surge rating, and you should test it on a rainy day before you need it. A unit with 2,400 watts of output and a high surge ceiling handles most residential sump pumps.

Well pumps are tougher. A typical 1/2 HP submersible draws up to about 1,000 watts running and several times that for an instant at startup, and most well pumps are 240-volt and hardwired. A standard portable power station outputs 120 volts, so it cannot run a 240-volt pump at all. You need a 240-volt-capable unit, connected by an electrician through an inlet and transfer switch. We compare those in power stations that can run a well pump, and cover the other workarounds, including the store-water-instead option, in the well pump backup power guide.

What a power station cannot realistically run

An honest list saves you a bad surprise during a storm, so here it is.

Central air conditioning is out. The draw is enormous and continuous, beyond any portable unit.

Electric resistance heat is technically runnable and practically pointless. A 1,500-watt space heater drains a 2,000Wh battery in a little over an hour. If you need outage heat, the answer is the gas furnace plus transfer switch above, or blankets and a small heater used in short bursts, not a battery running resistance heat all night.

Electric ranges, water heaters, and dryers are all 240-volt, multi-thousand-watt appliances. During an outage you cook on a camp stove or grill, outdoors.

Whole-house everything-at-once is also not what these are for. A power station is a triage tool. You pick the fridge, the phones, the router, the CPAP, and a lamp, and you let the rest of the house sleep.

The napkin math for any appliance

You can answer your own “will it run my X” question in three steps.

First, find the appliance’s running watts, usually on a label on the back or in the manual. Second, check the station’s continuous output is comfortably above it, with surge headroom if there is a motor or compressor involved. Third, estimate runtime: take the battery’s watt-hours, multiply by 0.85 for inverter losses, and divide by the running watts. A 1,056Wh battery on a 60-watt load is about 1,056 times 0.85 divided by 60, call it 15 hours.

For loads that cycle, like a fridge, divide by the average draw rather than the running draw, which is why real-world fridge runtime beats the naive math.

How do you recharge during a multi-day outage?

A long outage turns into a refilling problem. You have three ways to refill:

• Wall power when the grid comes back for a while. Current LiFePO4 units refill most of the way in under 90 minutes.
• Your car, slowly, while you drive.
• Solar panels, which let you refill every sunny day. Check the solar input limit: compact units take around 220 watts, big ones up to 1,200.

A battery keeps food cold, not plates full, so pair it with the right foods to stockpile for a power outage.

If you are sizing a unit around multi-day resilience, start from the what size power station do I need walkthrough, then compare the specific models in our best portable power stations roundup.

The quick reference table