How Long Will a Power Station Run a Fridge Freezer?
A power cut on a winter evening. A hunt for the torch. An argument about who didn’t put it back where it belongs.
The kids thought it was brilliant, right up until the novelty wore off. And then we both had the same thought at the same time. The freezer. Full of the Christmas food we had just bought. Not the lights, not the wifi. The freezer, and all that Marks and Spencer festive stuff inside it. Remember, it’s not just food, it’s… we’ll let you finish that one in your head.
So this is the question we went away and answered properly. If you have a power station in the cupboard, or you are thinking about buying one, will it keep the fridge freezer going, and for how long.
By Martin· Nest Nomad & Beyond · Last Updated September 2026
Quick Answer
Question | The short version |
Will a power station run a fridge freezer? | Yes, easily. Almost any 1kWh unit will do it |
How long on 1kWh? | 16 to 27 hours, about 20 for a typical UK fridge freezer |
How long on 2kWh? | 31 to 53 hours, about 40 for a typical one |
What does a fridge freezer actually draw? | About 35W averaged over a day, not the 150W on the plate |
What size should most people buy? | 1kWh for peace of mind, 2kWh if you are planning for storms |
The bit everyone gets wrong | Losses are a fixed draw, not a percentage. Most guides overstate runtime |
The bit nobody mentions | Whether it switches over on its own while you are out |
How Much Power a Fridge Freezer Actually Uses
This is where most of the confusion starts.
Look at the plate on the back of your fridge freezer and you might see 150W, or 200W. Multiply that by 24 hours and you get a frightening number, and a lot of people stop right there and assume a power station has no chance.
But the compressor does not run all the time. It cycles on and off to hold the temperature, so on a normal day it is only actually working for about a third of it.
The Number That Matters, Not the One on the Plate
What you want is the daily figure.
A typical UK fridge freezer uses between 200 and 450 kWh a year. That works out at roughly 0.5 to 1.2 kWh a day, and an efficient family sized one sits around 0.85 kWh.
Averaged across the whole day, that is about 35W of continuous draw, even though the compressor pulls 50W to 200W while it is actually running.
Want your own number rather than an average? A plug in energy monitor left on the fridge for a few days will tell you exactly. It’s a very geeky thing to do, but hey, each to their own.
What Size Power Station You Need
Here is the sizing, based on that daily figure.
Power station | Efficient (0.55 kWh/day) | Typical family (0.85 kWh/day) | Older or large (1.2 kWh/day) |
500Wh | 13 hours | 10 hours | 8 hours |
1kWh | 27 hours | 20 hours | 16 hours |
2kWh | 53 hours | 40 hours | 31 hours |
3kWh | 81 hours | 61 hours | 47 hours |
Those figures already account for the losses properly, which is where most guides go wrong. More on that further down.
For most households, 1kWh gets you through an evening and a night comfortably. 2kWh gets you through most of a long outage. Anything beyond 3kWh is a different conversation, and usually a permanently installed one.
How Long Do Power Cuts Actually Last?
Worth knowing before you spend anything, because it tells you which row of that table you need.
Ofgem’s figures put the average UK home at 0.4 power cuts a year, totalling about 38 minutes. Most cuts are short. Plenty of them are over before you have found the torch.
But an average is no use to you when you are the one with a full freezer. The number to plan against is the standard your network operator has to meet. In normal weather they have 12 hours to get you back on. In severe weather it is 24 or 48 hours depending on the incident. If they miss the 12 hour standard you can claim compensation, currently £95, with more for each further 12 hours.
So the sizing question rather answers itself. A 1kWh unit covers the normal weather standard comfortably. A 2kWh unit covers the severe weather backstop, which is the storm scenario people are actually worried about.
What We Measured
We have run the same 12V compressor fridge off three different 1kWh power stations, on separate trips
Power station | Capacity | Observed draw | Runtime on one charge |
EcoFlow Delta 3 | 1,024Wh | around 50W | about 14.5 hours |
Anker SOLIX C1000 Gen 2 | 1,024Wh | around 64W | 13.5 to 14 hours, 15.5 with two hours of afternoon sun |
AFERIY P180 | 1,024Wh | not logged | 13.5 to 13.75 hours |
All three landed within about an hour of each other. Same capacity, same fridge, near enough the same result.
Which tells you something useful. Capacity is what decides runtime. The badge on the front does not.
The Thing Every Other Guide Gets Wrong
Stay with us, because this is the bit that makes the numbers above trustworthy.
Almost every guide you will read tells you to knock about 15% off the capacity for losses. We said exactly the same thing in an earlier draft of this article. It is wrong, and our own testing is what showed it up.
A power station does not just lose a percentage. The inverter draws a small amount of power simply being switched on, and that draw is fixed. It does not get smaller when the fridge does.
You can see it in our own numbers:
• The Delta 3 gave 14.5 hours at around 50W. That is 725Wh to the fridge, out of a 1,024Wh battery. The missing 299Wh works out at about 21W of overhead.
• The Anker C1000 Gen 2 gave 13.75 hours at 64W. That is 880Wh delivered, leaving 144Wh, or about 10W of overhead.
Why does that matter? Because on a light load the overhead takes a much bigger bite. Fifteen watts on top of a 64W camping fridge is neither here nor there. Fifteen watts on top of a 35W kitchen fridge freezer is nearly half as much again.
Run it properly and a 1kWh unit gives a typical UK fridge freezer about 20 hours, not the 25 you get from the lazy percentage sum. Still a night and well into the next day. Still comfortably past the 12 hour restoration standard. Just not 25.
Why Your Kitchen Is an Easier Job Than Our Camping Fridge
One piece of good news.
That was a camping fridge, and it pulled 50W to 64W more or less continuously. A domestic fridge freezer cycles, so across a full day it averages nearer 35W. Your kitchen is the lighter load, by some margin.
The Surge Nobody Mentions
A fridge compressor does not start gently.
For a fraction of a second as it kicks in, it can pull two to three times its running wattage. That is what catches people out with smaller units. A power station rated at 300W continuous might handle a fridge that only draws 120W while running, right up until the compressor starts and the whole thing trips.
Check the surge or peak rating, not just the continuous one.
Most 1kWh units are fine. The Delta 3 is rated 1,800W continuous and 3,600W peak. The C1000 Gen 2 is 2,000W continuous and 3,000W peak. Anything much smaller and you want to test it before you rely on it.
Manual or Automatic, and Why It Decides Everything
Here is the thing we got wrong at first, and it is why the runtime numbers are only half the story.
There are two completely different ways of doing this.
Manual. The power goes off, you notice, you go and plug the fridge into the power station. Fine if you are in. Useless if you are at work, asleep, or away for a weekend. And let’s be honest, when the power goes off in our house we usually only notice when the oven timer needs resetting, which means we were either out at work or fast asleep in bed.
A freezer full of food does not care how big your battery is if nobody was home to connect it.
Automatic. The power station sits permanently between the wall and the fridge, passing power through. When the mains drops it takes over by itself and the fridge never stops running. This is usually called UPS or EPS mode.
Most decent power stations will do this if you leave them plugged in with the fridge connected. Anker quote a 10ms switchover on the C1000 Gen 2. EcoFlow’s Delta range quotes around 30ms depending on the model. Worth checking yours.
The Millisecond Thing, Our One Gripe
You will see 10ms used as a selling point on these.
For a computer or a NAS drive that number genuinely matters, because a longer gap means a reboot and possibly lost data. For a fridge it really does not. A compressor will shrug off a gap of several seconds without noticing.
So when you are comparing, the question is whether it switches over automatically at all. Not whether it does it in 10ms or 30ms.
There is also a newer category built specifically for this job. Slim units designed to live behind the fridge permanently and take over on their own. BLUETTI’s FridgePower is the obvious example, 2,016Wh at £999, and it does what it says on the tin. We have not tested it, so treat its runtime figures as BLUETTI’s rather than ours.
There is also a catch that applies to every one of these, and it is worth knowing before you spend anything.
Can You Actually Reach the Plug?
Ours is a built in fridge freezer.
It sits in a housing unit, and there is no way to get behind it for a large backup power supply to sit. There is also no way Carina would allow me to stick a 75mm thick battery pack to the wall in plain sight.
Which means a permanently installed backup, however good it is, is not an option for us at all.
This applies to an awful lot of UK kitchens, and we have not seen another guide mention it once. So before you buy anything designed to sit inline, go and have a look. Can you physically get to the socket your fridge is plugged into, and can you hide the battery? In some integrated kitchens the socket is in the cupboard next door and it is fine. In others it is behind the appliance, and that is that.
If you cannot reach it, you are in manual territory. The honest advice then is to buy a portable unit you can carry over and plug in, and accept that somebody needs to be home.
How Long Food Lasts Without Power
Worth knowing, because it tells you how much runtime you actually need.
Food Standards Scotland says a fridge should keep food at a safe temperature for up to four hours, and a freezer should stay frozen for up to 48 hours if it is full, or about 24 hours if it is half full. Keep the doors shut as much as you can, because every opening costs you.
They also note that during a power cut it should be safe as long as the fridge does not rise above 8°C. If it goes above that, eat anything that normally needs refrigerating within four hours.
So the freezer is not as fragile as people think. A full one buys you a day or two on its own. What you are really protecting against is the longer outage, or the one that starts while you are out.
What We’d Actually Buy
With the government now asking households to prepare for outages and be a bit more resilient, we are keeping a 1kWh unit charged and near the kitchen. On our own testing that is a night and most of the following day for a fridge freezer, which covers the great majority of outages.
We would go for either the Anker SOLIX C1000 Gen 2 or the EcoFlow Delta 3. The Anker just shades it for us on size, since it takes up less room in a cupboard, and it recharges fastest of the three at 49 minutes flat to full.
If you are planning specifically for storm season rather than the odd evening, step up to
2kWh and stop worrying about it.
Where to Buy in the UK
Unit | Capacity | Best for | Where |
Anker SOLIX C1000 Gen 2 | 1,024Wh | Most households, smallest footprint | |
EcoFlow Delta 3 | 1,024Wh | Fastest solar top up | |
AFERIY P180 | 1,024Wh | Value | |
BLUETTI FridgePower | 2,016Wh | Permanent install, if you can reach the socket |
Frequently Asked Questions
Can a power station run a fridge freezer?
Yes, comfortably. A fridge freezer is one of the easier things to run off a power station, because its average draw is far lower than the figure on its rating plate.
What size power station do I need to run a fridge?
For a typical UK fridge freezer, 1kWh gives you about 20 hours and 2kWh gives you about 40. Anything from 1kWh up will do the job.
How long will a 2kWh battery run a fridge?
Between 31 and 53 hours depending on your fridge freezer, and about 40 hours for a typical family sized one.
How many watts does a fridge freezer use in the UK?
About 35W averaged across a full day, though the compressor pulls 50W to 200W while it is actually running. Over a year that is 200 to 450 kWh.
How long will a fridge run off a 12V battery?
Our 12V camping fridge ran for about 14 hours on a 1,024Wh power station. A household fridge freezer is a lighter load and will run longer.
Will a power station switch over automatically when the power goes off?
Most will, if you leave them plugged in with the fridge connected and UPS or EPS mode enabled. Check your model, because it is the single most important feature for this job.
Do I need to worry about the startup surge?
Only with small units. A fridge compressor briefly pulls two to three times its running watts on start up. Any 1kWh power station with a 1,800W or higher peak rating handles it without blinking.
How long will food last in a freezer without power?
Up to 48 hours if the freezer is full, or about 24 hours if it is half full, according to Food Standards Scotland. A fridge is safe for about four hours.
How long do power cuts last in the UK?
The average home loses power for about 38 minutes a year across 0.4 outages. Your network operator has 12 hours to restore supply in normal weather, or 24 to 48 hours in severe weather.
Can I claim anything if the power is off for a long time?
Yes. If your network operator misses the 12 hour standard in normal weather you can claim compensation, currently £95, with more for each further 12 hours.
Should I buy 1kWh or 2kWh?
1kWh if you want peace of mind for an evening and a night. 2kWh if you are specifically planning for storm season and want to cover a two day outage.
Can I run other things at the same time?
You can, but every watt comes off the fridge’s runtime. If the freezer is the priority, keep the phone charging and the lamps on something else.
Does leaving it plugged in all the time damage the battery?
Modern LiFePO4 units are designed for it, and the Delta 3, C1000 Gen 2 and P180 are all rated for around 4,000 cycles or more. Leaving it in UPS mode is normal use.
Can you run a TV off a power station?
Easily. A modern TV draws far less than a fridge compressor, so it is the runtime rather than the capability that limits you.
Will my boiler work in a power cut?
Almost certainly not, because gas boilers need mains electricity for the controls and the pump. That is a bigger question and we are covering it separately.
What about the freezer in the garage?
Same maths, but garages get colder, which usually means the compressor runs less and your runtime improves.
Related Reading
Anker SOLIX C1000 Gen 2 reviewThe unit that came out fastest to recharge in our testing, at 49 minutes flat to full.
EcoFlow Delta 3 reviewWhere the 14.5 hour fridge runtime in the table above came from.
AFERIY P180 reviewA week off grid with the P180 doing the heavy lifting.
Best portable power station UKIf you want the head to head rather than the sizing, this is where we compare them properly.
EcoFlow Glacier reviewThe portable fridge we bought ourselves and took to Lake Garda, if you are thinking about the other end of the problem.
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