Best cool boxes and 12V fridges for power cuts, camping and the car UK (2026)
A cool box earns its place in a prepared home for one job: holding chilled food, and for some households fridge medicines, at a safe temperature when the kitchen fridge cannot, in a power cut, on a campsite or on a long drive. The three kinds sold in the UK do that very differently. A passive box is insulation and ice; a thermoelectric box cools a set amount below the air around it; a compressor fridge makes its own cold. We compare what each maker states about temperature and time against the Food Standards Agency advice of 5°C or below. We have not used any of these ourselves.
By Tom Calder · Updated 21 October 2026 · 7 products, all price-tracked
Our picks by type
Photo: EcoFlowEcoFlow GLACIER Classic 55L
A household that wants a large fridge-freezer that can keep running through a long power cut or a camping week.
Photo: AmazonSubcold MOBI45
Day trips, camping weekends, and holding chilled food on ice once the fridge starts to warm in a long power cut.
as of 21 Oct 2026, 10:37 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.All 7 compared
| Cool box | Type | Capacity | Power | Cooling (maker) | Price |
|---|---|---|---|---|---|
Compressor, dual zone · 55 L · Mains, 12/24V car, solar, 298Wh battery · 4°C for up to 39 h on battery A household that wants a large fridge-freezer that can keep running through a long power cut or a camping week. | Compressor, dual zone | 55 L | Mains, 12/24V car, solar, 298Wh battery | 4°C for up to 39 h on battery | £829 at EcoFlow Checked 21 OctIn stockCheck price → |
Our verdictOur verdictResearched The 55L is the biggest GLACIER Classic and, with its two temperature zones, can hold fresh and frozen food at once. EcoFlow quotes up to 39 hours at 4°C on the supplied 298Wh battery, tested at 25°C ambient in Eco mode, and the unit can also be recharged from mains, a 12/24V car socket or solar. Against the cheaper passive boxes on this page it is a different class of kit: it makes its own cold, but it is heavy and costs several times more. Best for A household that wants a large fridge-freezer that can keep running through a long power cut or a camping week. Good
Worth knowing
Who shouldn't buy it: You only need food kept cold for a day trip; a passive box or the 35L is cheaper and lighter. | |||||
Compressor, dual zone · 45 L · Mains, 12/24V car, solar, 298Wh battery · 4°C for up to 39 h on battery A family that wants dual-zone cooling without the extra bulk of the 55L. | Compressor, dual zone | 45 L | Mains, 12/24V car, solar, 298Wh battery | 4°C for up to 39 h on battery | £729 at EcoFlow Checked 21 OctIn stockCheck price → |
Our verdictOur verdictResearched The 45L sits between the other two GLACIER Classic sizes and, like the 55L, has two temperature zones. EcoFlow quotes up to 39 hours at 4°C on the bundled battery under its test conditions (25°C ambient, Eco mode). It suits a household that wants a power-cut fridge that doubles as a car or camping fridge, and it avoids the weight of the 55L. Best for A family that wants dual-zone cooling without the extra bulk of the 55L. Good
Worth knowing
Who shouldn't buy it: A single-zone unit would do; the 35L is lighter and lower in cost. | |||||
 Compressor, single zone · 35 L · Mains, 12/24V car, solar, 298Wh battery · 4°C for up to 43 h on battery A small household that wants a compact fridge for power cuts, camping or the car. | Compressor, single zone | 35 L | Mains, 12/24V car, solar, 298Wh battery | 4°C for up to 43 h on battery | £629 at EcoFlow Checked 21 OctIn stockCheck price → |
Our verdictOur verdictResearched The 35L is the smallest GLACIER Classic and has one zone that switches between fridge and freezer duty. EcoFlow quotes the longest runtime of the range here, up to 43 hours at 4°C on the bundled battery, tested at 25°C ambient in Eco mode. It is the practical pick for a self-powered fridge holding the essentials, and far more capable than a thermoelectric box, though it costs more. EcoFlow makes no medicine-storage claim for it. Best for A small household that wants a compact fridge for power cuts, camping or the car. Good
Worth knowing
Who shouldn't buy it: You need chilled and frozen food stored together; step up to the 45L or 55L. | |||||
Passive (ice packs or ice) · 45 L · None · Cold for days (no figure given) Day trips, camping weekends, and holding chilled food on ice once the fridge starts to warm in a long power cut. | Passive (ice packs or ice) | 45 L | None | Cold for days (no figure given) | £99.99 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A 45L wheeled box with PU foam insulation and a drain, at 5.7 kg empty. Subcold says it will hold about 60 cans or 24 kg of ice and stay cold for days, but gives no temperature-over-time figure. The FSA says a closed fridge stays cold for up to 4 hours and a full, closed freezer stays frozen for up to 48, so in a long outage this box is a sound, low-cost place to move chilled food packed with ice, though it needs topping up and cannot hold a set temperature the way a powered fridge can. Best for Day trips, camping weekends, and holding chilled food on ice once the fridge starts to warm in a long power cut. Good
Worth knowing
Who shouldn't buy it: You need cold for several days without fresh ice; a powered compressor fridge fits better. | |||||
 Passive (ice packs or ice) · 70 L · None · Cold for days (no figure given) Big families, large gatherings, or holding a full fridge's worth of chilled food on ice in a long power cut. | Passive (ice packs or ice) | 70 L | None | Cold for days (no figure given) | £139.99 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The 70L sibling of the MOBI45 is the largest passive box on this page, with the same PU foam and HDPE build and wheels. Subcold states it takes about 100 cans or 32 kg of ice, and quotes cold for days without a time figure. Choose it when volume matters more than portability, and expect to need a lot of ice to keep a box this size below 5°C. Best for Big families, large gatherings, or holding a full fridge's worth of chilled food on ice in a long power cut. Good
Worth knowing
Who shouldn't buy it: You only need to chill a few items; the 45L is easier to carry and cheaper to ice. | |||||
 Passive (ice packs or ice) · 30 L · None · Under 5°C for up to 46 h A small household's day trips, or a compact box for the essentials during a power cut. | Passive (ice packs or ice) | 30 L | None | Under 5°C for up to 46 h | £69.99 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A 30L wheeled box with a telescopic handle and PU foam insulation. It is one of the few passive boxes here where the maker gives a food-relevant figure: Subcold says contents stay under 5°C for up to 46 hours and under 10°C for up to 56 hours, though it does not state the ice load or room temperature behind that. That makes it a reasonable small-scale power-cut box if you pack frozen blocks, with the 45L better when a whole fridge needs emptying. Best for A small household's day trips, or a compact box for the essentials during a power cut. Good
Worth knowing
Who shouldn't buy it: You need to hold a full fridge's worth of food; pick the 45L or 70L. | |||||
 Thermoelectric · 28 L · 12V DC or 230V AC, 55W · 15-20°C below ambient at 25°C Keeping drinks and lunch cool on a car journey or at a campsite with a plug, at modest cost. | Thermoelectric | 28 L | 12V DC or 230V AC, 55W | 15-20°C below ambient at 25°C | |
Our verdictOur verdictResearched A 28L plug-in cool box that cools by the Peltier effect rather than a compressor, so Subcold says it only reaches 15 to 20°C below the surrounding temperature, measured at 25°C. In a warm car or a hot room it will not reach the 5°C or below that the Food Standards Agency advises for chilled food, so treat it as a way to keep food cool rather than a fridge. It does run from a 12V car lead, mains, or a power station, which is handy in a power cut for short spells. Best for Keeping drinks and lunch cool on a car journey or at a campsite with a plug, at modest cost. Good
Worth knowing
Who shouldn't buy it: You need food reliably at 5°C or below, or you want to store medicine; Subcold makes no medicine claim, so a compressor fridge, or advice from your pharmacist, fits better. | |||||
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Before you buy
Start with temperature, not litres.
The Food Standards Agency says a fridge should sit between 0 and 5°C, a freezer at about -18°C, and chilled food must stay below 8°C. A passive box holds whatever its ice gives it, and that fades as it melts; only Subcold's Chilly30 carries a food-relevant figure, under 5°C for up to 46 hours, with no test conditions given. A thermoelectric box cools relative to the surrounding air: Subcold states 15 to 20°C below ambient at 25°C for its Euro30, so roughly 5 to 10°C in a 25°C room and warmer in a hot car. Only a compressor fridge holds a set temperature.
Decide what will power it.
A passive box needs nothing: in a blackout there is no battery to be flat and no socket to be dead. A thermoelectric box needs 12V or 230V the whole time; unplugged, it is an insulated box. A compressor fridge runs from mains, a car socket, solar or, on the EcoFlow GLACIER Classic, a plug-in battery, with the maker quoting up to 39 or 43 hours at 4°C by model, tested at 25°C in Eco mode. Treat that as a best case: heat, a freezer setting and an open lid all shorten it, and the battery only helps if charged before the cut.
Mind the car's 12V socket.
Subcold rates the Euro30 at 55W, drawn for as long as it is plugged in, which can flatten a parked car's starter battery; run it while driving and move it to the mains or a power station when you stop. Never run a petrol or diesel generator, or any engine, indoors or in a garage to power a fridge, and keep a generator well away from doors and windows: exhaust indoors is a carbon monoxide risk. Rechargeable fridge batteries are lithium cells, so charge them on a hard surface in view, with the maker's charger, and read our lithium battery fire safety guide first.
Size it for the job you will actually give it.
Capacities here run from 28 to 70 litres. A box packed full with food and frozen blocks holds its cold better than a half-empty one, so choose a size you can fill rather than the biggest on offer. For a power cut, think about what you would actually move: the most perishable chilled food, not the whole fridge. The passive boxes weigh 5.6 to 8.2 kg before any ice, so wheels and a drain earn their keep, and the compressor fridges weigh about 20 to 25 kg before food: a two-person lift once loaded.
Finally, be honest about medicines.
Insulin, some eye drops and several injectable medicines need to stay between 2 and 8°C, and a box that cannot show you its temperature cannot prove it is doing that. None of the makers on this page states that its box suits medicines, so ask your pharmacist first. A compressor fridge is the only kind here that holds a set temperature, though keep medicines out of a freezer zone, and frozen blocks in a passive box can freeze medicines placed against them, which ruins insulin. Keep a fridge thermometer in whichever you use, and read our guide to fridge medicines in a power cut.
We verify every product's specifications against at least two independent sources, re-check its UK price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labelled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test — and commissions never change a ranking either way. Read our full methodology →
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Common questions
How long will a cool box keep food safe without power?
It depends on the ice, the room and the lid, and most makers do not say. Among the boxes here, only Subcold's Chilly30 carries a figure: under 5°C for up to 46 hours, with no stated test conditions. In a power cut, pack any passive box with frozen blocks, keep a fridge thermometer inside and open it as little as possible. The FSA says chilled food that has been at 8°C or above for more than 4 hours should be thrown away.
Do thermoelectric 12V cool boxes actually get cold enough for food?
Not reliably. A thermoelectric box cools to a set amount below the surrounding air, not to a fixed temperature. Subcold states 15 to 20°C below ambient at 25°C for the Euro30 here, so in a 25°C room it may reach 5 to 10°C, and in a 30°C car it will sit above the 5°C the FSA wants for chilled food. They are fine for drinks and a packed lunch on a journey. For raw meat, dairy or medicines over any length of time, a compressor fridge is the right kind.
Is a 12V compressor fridge worth it for power cuts?
Only if you expect long or frequent cuts, or have something that must stay cold. The FSA says a shut fridge stays cold for up to 4 hours and a full freezer for up to 48, covering most UK outages. A compressor fridge with its own battery, such as the EcoFlow GLACIER Classic, is quoted at up to 39 to 43 hours at 4°C under test conditions, so it bridges a day-long cut, but it must be charged beforehand and costs many times what a passive box does.
Can I keep insulin in a cool box during a power cut?
Check with your pharmacist or diabetes team first, and do not rely on a box that cannot show you its temperature. Unopened insulin is stored at 2 to 8°C, and in-use pens are usually kept at room temperature for a limited time, so a short cut often needs no action. None of the makers here states that its box suits medicines. If you use one, keep a thermometer inside and never let insulin touch frozen blocks, because freezing spoils it. Our fridge medicines guide covers replacement.
Will a cool box drain my car battery?
A powered one can. The Euro30 here is rated at 55W, drawn for as long as it is plugged in, and on a parked car that comes straight from the starter battery, so run it while driving and unplug it when you stop. Many compressor fridges have a low-voltage cut-off setting; check the manual for the model you buy. At home in a cut, a power station or the fridge's own battery is the better supply; never run a car engine in a garage.
Can I just use my freezer and some ice blocks instead?
For most homes, yes, and it is the cheapest plan. Keep a few freezer blocks or bottles of water frozen. If a cut looks set to last beyond 4 hours, move the most perishable chilled food into any insulated box with the frozen blocks around it, then keep the freezer shut. The FSA says a full freezer stays frozen for up to 48 hours and a half-full one for about 24, so keeping it full, even with bottles of water, buys time.
