Electric car battery capacity ranked: which EVs have the biggest battery?

The Range Rover Electric has the biggest battery of any electric car in the EV Compared UK dataset on 10 November 2026, with 118.5 kWh of usable capacity. The Mercedes EQS SUV (118 kWh) and BMW i7 (112.5 kWh) come next, while at the other end the Citroen Ami quadricycle makes do with 5.4 kWh.

Battery capacity is the headline number on every electric car’s spec sheet, and it is easy to read it as a straight proxy for range. It is not. A large, heavy SUV needs a large battery just to match the range a lighter, more aerodynamic car gets from a much smaller one. This guide ranks the biggest batteries on sale in the UK, explains how capacity turns into miles, and works out what a really big pack costs to fill.

What is electric car battery capacity?

Electric car battery capacity is the amount of energy the battery pack can store, measured in kilowatt hours (kWh). One kWh is the energy a 1 kW load uses in an hour, and it is the same unit as on your home electricity bill, which makes running costs easy to work out.

Makers quote two figures. Gross capacity is everything the cells can hold. Usable, or net, capacity is the part the car lets you draw on: a slice at the top and bottom is held back as a buffer to protect the cells. Porsche quotes a gross capacity of 105 kWh for the Taycan’s Performance Battery Plus, while our dataset records 97 kWh usable for the car. Range comes from the usable figure, so that is what we rank by.

Which electric cars have the biggest battery?

The Range Rover Electric has the biggest usable battery of the cars in our dataset, narrowly ahead of the Mercedes EQS SUV. The table lists the twelve biggest. Our own figures use one method throughout: efficiency is WLTP miles divided by usable kWh, and a full charge at home is priced at the 6.5p/kWh Intelligent Octopus Go off-peak rate, ignoring charging losses (see our full costing methodology).

Car	Usable battery	WLTP range	Miles per kWh	Full charge at home	List price, Nov 2026
Range Rover Electric	118.5 kWh	372 miles	3.14	£7.70	£154,070
Mercedes EQS SUV	118 kWh	400 miles	3.39	£7.67	£129,480
BMW i7	112.5 kWh	452 miles	4.02	£7.31	£104,230
Mercedes EQS	112 kWh	490 miles	4.38	£7.28	£91,765
Porsche Taycan	97 kWh	434 miles	4.47	£6.31	£88,465
Audi e-tron GT	97 kWh	384 miles	3.96	£6.31	£88,605
MG IM6	96.5 kWh	388 miles	4.02	£6.27	£48,495
Mercedes EQE	96 kWh	422 miles	4.40	£6.24	£69,365
Mercedes EQE SUV	96 kWh	372 miles	3.88	£6.24	£76,870
Porsche Macan Electric	95 kWh	398 miles	4.19	£6.18	£69,865
BMW iX	94.8 kWh	374 miles	3.95	£6.16	£75,405
Mercedes C-Class electric	94 kWh	452 miles	4.81	£6.11	£57,995

Several large electric cars in our dataset, including the Porsche Cayenne Electric, Kia EV9, Hyundai Ioniq 9, Polestar 3 and Mercedes G 580, have no usable capacity recorded, so we leave them out rather than guess.

The table shows why capacity alone misleads. The Mercedes EQS goes 118 miles further on the WLTP test than the Range Rover Electric with 6.5 kWh less battery, and the C-Class electric matches the BMW i7’s 452 miles with 18.5 kWh less. A low, slippery saloon simply uses less energy per mile than a tall, square SUV weighing close to three tonnes. The MG IM6 stands out on value: at £48,495 it costs £125 of list price for every mile of WLTP range, against £414 for the Range Rover Electric.

How do you calculate range from battery capacity?

Range is usable battery capacity multiplied by efficiency. The Range Rover Electric has 118.5 kWh usable and returns 3.14 miles per kWh on our method, and 118.5 × 3.14 gives its official 372 miles, or roughly 599 km.

Two things pull the real figure down. First, the official consumption figure includes energy lost between the plug and the battery, so Auto Express quotes the Range Rover at up to 2.8 miles per kWh rather than our 3.14. Second, motorway speeds and cold weather raise consumption. JLR itself quotes a real-world range of 535 km (333 miles) on a standard route, and Auto Express’s tester found Land Rover’s real-world figure of around 330 miles achievable in the Scottish Highlands.

The same sum works for any electric car battery capacity calculator: put in the usable kWh and a realistic miles per kWh for your driving, and you have your range.

Worked example: what does a 118.5 kWh battery cost to run?

A full charge of the Range Rover Electric costs £7.70 at home on an off-peak tariff and £97.17 on a public rapid charger. These are EV Compared’s figures at 6.5p/kWh (Intelligent Octopus Go), 26.32p/kWh (Ofgem’s price cap for October to December 2026) and 82p/kWh (Zapmap’s rapid and ultra-rapid average for October 2026).

Range Rover Electric	Off-peak home, 6.5p	Price cap, 26.32p	Public rapid, 82p
Full charge, 118.5 kWh	£7.70	£31.19	£97.17
Pence per mile	2.1p	8.4p	26.1p
8,000 miles a year	£166	£671	£2,090

Charging habits matter far more than battery size here: the same 8,000 miles cost £166 on a smart tariff and £2,090 if every mile came from rapid chargers. For comparison, the Mercedes C-Class electric would cost about £108 for 8,000 miles at the off-peak rate, and the MG IM6 about £129.

A big battery takes a long time to fill at home. On a 7 kW wallbox the Range Rover needs 16.9 hours from empty to full by our method; Auto Express quotes 19 hours to 80%, which allows for real charging losses. Most owners top up rather than start from empty, but if you plan to install a home charger for a large battery, check your supply can support it.

Does a bigger battery take longer to rapid charge?

A bigger battery holds more energy, so it needs a faster charger to add miles at the same rate. JLR quotes 10 to 80% in about 22 minutes on a 350 kW charger for the Range Rover Electric, which works out at 118 miles added in 10 minutes on our method (assuming 70% of the battery goes in during the 10 to 80% time). JLR’s own claim is 137 miles in 10 minutes.

Smaller, more efficient packs that charge faster can beat that. On the same method the MG IM6 adds about 160 miles in 10 minutes and the Porsche Taycan about 169, while the Mercedes EQS SUV, with a 31-minute 10 to 80% time, adds about 90. Frequent ultra-rapid charging has its own cost: fleet data shows rapid charging wears batteries faster, which is another reason to do most charging at home.

What are the different types of EV battery?

Almost every electric car uses a lithium-ion battery, and the two main chemistries are NMC (nickel manganese cobalt) and LFP (lithium iron phosphate). LFP is the cheaper of the two, as the price figures below show, while NMC turns up in large, expensive packs: Electrifying reports that the updated Mercedes EQS has a 122 kWh NMC battery.

The way cells are packaged differs too. The Range Rover Electric uses 344 prismatic (flat, box-shaped) cells stacked in two layers, while the new BMW i7 uses BMW’s Gen6 round cells. BYD takes another route with its Blade battery design, and MG is moving to a semi-solid-state battery for the MG4 Urban.

How much does an electric car battery cost?

BloombergNEF’s survey, published in December 2025, put the average electric vehicle battery pack at $99 per kWh, a second year below $100. Across all uses, LFP packs averaged $81 per kWh and NMC packs $128, and European prices ran 56% above China’s.

At the $99 average, a 118.5 kWh pack works out at about $11,700 of battery, before the car around it. That helps explain why the biggest batteries sit in six-figure cars. Replacing a pack out of warranty costs far more than its cell value, as our guide to the cost of replacing an EV battery sets out.

How heavy is a big EV battery?

JLR does not publish the Range Rover Electric’s pack weight, but Auto Express gives the car a kerb weight of 2,810 kg. That mass is part of why its efficiency trails the big saloons. It also tows: the Range Rover Electric is rated for 2,500 kg, and a big battery helps absorb the extra energy a trailer uses. Our guide to electric cars that can tow covers what happens to range with a caravan behind.

Has electric car battery capacity grown by year?

Battery capacity keeps rising, often without the pack getting bigger. Electrifying reports that the updated Mercedes EQS moves from 118 kWh to 122 kWh in a pack of the same physical size, with UK sales due later in 2026. Porsche replaced the Taycan’s 89 kWh standard battery with its 105 kWh Performance Battery Plus for the 2025 model year, according to Motoring Research.

The trend is not only upwards. Since July 2026 Nissan has offered the Leaf with a 52 kWh battery (280 miles WLTP) as well as the 75 kWh version (386 miles), letting buyers pay less for capacity they do not need.

Which electric car has the most reliable battery?

The most useful guide to battery reliability is the warranty. JLR covers the Range Rover Electric’s battery for eight years or 100,000 miles. Regulation is catching up too: Euro 7 brings battery durability rules to Great Britain. Buying used, a health report matters more than capacity on paper; see how to check a used EV’s battery.

How do you know if a car is a plug-in hybrid?

A plug-in hybrid has both a petrol engine and a charging port, and its battery is a fraction of an electric car’s. The MG HS plug-in hybrid has a 23.2 kWh battery and a 75-mile electric-only range; the Omoda 9 plug-in hybrid has 34.46 kWh and a 90-mile electric-only range. If the spec sheet lists a fuel tank and an electric range under 100 miles, it is a plug-in hybrid.

Should you go fully electric instead?

If you can charge at home, a fully electric car with a mid-sized battery usually makes more sense than a plug-in hybrid. The 52 kWh Nissan Leaf is rated at 280 miles WLTP, nearly four times the MG HS plug-in hybrid’s 75 electric-only miles, so most weeks need no fuel at all. A plug-in hybrid still suits drivers who regularly cover long distances with no reliable rapid charging on the route.

What battery size do you actually need?

Buy the battery your longest regular journey needs, not the biggest you can afford. Our verdict, based on published data rather than our own driving: the Range Rover Electric’s 118.5 kWh battery suits buyers who tow, cover long distances and charge at home, where it costs £7.70 to fill. It does not suit anyone chasing efficiency: the Mercedes EQS and C-Class electric go further on less battery, and the MG IM6 gives 96.5 kWh for under a third of the price.