Best 12V Cool Boxes 2024
We find the best way to chill out this summer with a 12V electronic cool box for your car
Long journeys, whether a day trip or weeks in a camper van, invariably involve regular visits to cafés or motorway services. Doing this can be seriously expensive, so taking food and drink with you in a cool box is a practical way to save some money.
We reckon that 20-24 litres is about right for a smallish picnic, although for a family spread, 30 litres-plus would be better. Most boxes can run from the mains as well as 12V, making them more versatile. The same applies to boxes that can heat as well as cool.
The aim of any box is to maintain the temperature of food/drink that has already been cooled or heated. Most boxes work by using a simple motor in the lid and are on or off, with no control over temperature. For regular users and globetrotters, especially in hotter climates, a compressor box is a better bet. It’s quieter, more efficient and controllable, but costs extra and is heavier. We powered up eight examples to see which will keep you cool.
How we tested them
We ran each box at maximum power for two hours, both cooling and heating, and then logged the temperature decrease or increase. We also measured the temperature again after the box had been standing for an hour, to see how well the insulation worked.
Used - available now
2024 BMW
iX3
24,884 milesAutomaticElectric
Cash £30,871
2025 BMW
i4
13,251 milesAutomaticElectric
Cash £30,614
2025 BMW
i4
34,053 milesAutomaticElectric
Cash £26,006
2020 Hyundai
i30 N
72,908 milesManualPetrol2.0L
Cash £17,186After this, we assembled typical picnic contents (a two-litre bottle of soft drink, four plastic containers, large bags of crisps and various biscuits and cake) to see how well each box coped. We also rated each unit for practicality, ease of use, wheels, mains power, eco power option and build quality. Finally, we balanced all these factors against each box’s capacity and online prices.
Reviews:
Outwell Ecocool Lite Dark Blue
- Price: Around £74
- Capacity: 24 litres
- Mains: Yes
- Rating: 5 stars
- Website: outwell.com
Derived from a previous test winner, this Outwell box has had various updates. This time it cooled 18 degrees from ambient, losing a reasonable eight degrees after one hour, while it heated to a test best of 45 degrees. The price per litre is reasonable, at £3.07, as is the Ecocool Lite’s 4.2kg weight.
The controls are sliders for heat/cool and max/eco, with no selector for temperature. We fitted all our picnic inside – it was easier without a divider – but had to opt for a 1.5l drinks bottle, because a 2l one was too tall to fit in. Our winning box offers a good balance of performance and practicality.
Streetwize 24l Thermoelectric Cooler & Warmer Box LWKB2
- Price: Around £66
- Capacity: 24 litres
- Mains: Yes
- Rating: 4.5 stars
- Website: streetwize.co.uk
This box begged direct comparison with our test winner, because the basic specs are similar. It’s the lightest box on test (3.7kg) and this is reflected in average build quality. However, we like the three cup-holders on the quick-release lid.
With the same capacity as our winner, it didn’t cool as well (10 degrees) and lost one degree more after an hour. The heat performance gained 38 degrees in two hours. Usefully, it has three positions on the lid specifically for taller bottles, although only up to 1.5l, rather than 2l.
Streetwize 32l Thermoelectric Cooler & Warmer Box LWKB3
- Price: Around £85
- Capacity: 32 litres
- Mains: Yes
- Rating: 4 stars
- Website: streetwize.co.uk
The 32-litre Streetwize is the first of our larger-capacity boxes. It features a divider and, as with the smaller 24-litre model, a quickly removable lid with three cup-holders, which come in handy when the picnic starts.
The 12V and mains connections are on the lid, along with the various sliders for settings, although as with most of its test rivals, there is no temperature control. Its performance was average on cooling, dropping 12 degrees, but way off the best at heating, at 34 degrees. Yet its price and light weight (4.2kg) make it worth checking out.
Outwell Ecocool Slate Grey
- Price: Around £144
- Capacity: 34 litres
- Mains: Yes
- Rating: 3.5 stars
- Website: outwell.com
We like the lid that is divided into two sections, giving the option to lose less cool/warm air when it’s opened. We think the hollow ice-pack divider is a neat touch and a simple way to keep the temperature down, even when the unit is unplugged.
Cooling performance was okay, losing 14 degrees, and the heat gain was good at 40 degrees, while the temperature loss was impressive, at seven degrees. It stored 2l bottles in dedicated positions, plus all our picnic items. While the Outwell’s performance was better than the Streetwize 32l, its price and weight (a hefty 7kg) hindered its overall score.
Halfords 40l Electric Coolbox
- Price: Around £95
- Capacity: 40 litres
- Mains: Yes (& 24V)
- Rating: 3 stars
- Website: halfords.com
This 40-litre box is a monster that swallowed all our larger picnic gear, plus three 2l bottles in dedicated positions. But the penalty is the weight, 8.7kg plus contents, although a neat handle and two castors help when moving it around. While the £95 price seems high, the Halfords is the cheapest per litre, at £2.13.
The mains/12V cables are permanently fitted and it has three internal dividers. It has a selectable temperature control, but this only works on mains. Despite having no heating option, it’s still an impressive box.
Halfords 24l 12V Electric Coolbox
- Price: Around £60
- Capacity: 24 litres
- Mains: No
- Rating: 3 stars
- Website: halfords.com
The Halfords twins are particularly well made, with their lids shutting with a satisfying clunk. Unlike most rivals, the 24l box is 12V only, with a power cable permanently connected and stored in a neat cubby in the lid.
There are two bottle spaces inside, but not quite enough height for a 2l PET bottle due to the box’s motor in the lid. We got the rest of the picnic inside, but oddly it was more of a squash than the same-capacity Streetwize. While it’s reasonably priced for the size, it needs to heat as well to be really competitive.
Dometic TropiCool TCX35
- Price: Around £250
- Capacity: 33 litres
- Mains: Yes (& 24V)
- Rating: 3 stars
- Website: dometic.com
We like the great build quality and damped lid, with its spring-loaded single-handed catch. Soft-touch controls give seven heating and cooling modes, spanning 0-65 degrees. Its heat gain of 42 degrees and cooling of 17 degrees were second best on test.
With the motor at the base, the 33-litre storage space is uncluttered and has a single divider that can be placed in two slots. We like the two dedicated 2l bottle positions, and our large picnic easily fitted inside. The compressor unit is an impressive performer, although of course, it adds to the Dometic’s price.
Igloo ICF18 Mains or 12-24 Volt Electric Cool Box
- Price: Around £300
- Capacity: 19 litres
- Mains: Yes (& 24V)
- Rating: 2.5 stars
- Website: igloocoolers.co.uk
The ICF18 is a portable fridge, with the compressor adding to the weight (around 10.5kg) and the price. But it served up a stunning cooling performance; well within an hour it had dropped to an electronically limited zero degrees, with the best insulation result of just five degrees.
We like the digital display and the selectable temperature feature. While it’s the joint smallest and priciest unit in this test, the Igloo still has a divider, enough height for two 2l bottles and took our smaller picnic. You wouldn’t buy it for the occasional run out, but it would be a must for the serious hot-climate traveller.
Verdict
Outwell’s Lite model is a great performer and combines this with a good capacity at the right price. The Streetwize twins are very good value and still work well in all modes.
- Outwell Ecocool Lite Dark Blue
- Streetwize 24l Thermoelectric Cooler & Warmer Box LWKB2
- Streetwize 32l Thermoelectric Cooler & Warmer Box LWKB3
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