How to check the battery health of a used electric car (UK guide)

With a used petrol car, you worry about the engine. With a used electric car, it's all about the battery.

The good news: the UK's largest used EV battery study, covering around 8,000 cars, found an average battery health of about 95%. Most used EVs are in far better shape than people fear. But individual cars vary, so always check.

What is "state of health"?

State of health (SoH) is the battery's usable capacity now, as a percentage of its capacity when new. A car with 90% SoH can store about 90% of the energy it could when it left the factory, so it'll have roughly 90% of its original range.

How to check it

1. Ask for a battery health certificate. More dealers now provide one, including big groups such as Arnold Clark and Motorpoint. In one survey, 38% of drivers said a certificate would make them more likely to buy.
2. Use the car's own tools. The Nissan Leaf shows 12 battery bars on the dash, and newer Teslas have a battery test in the service menu.
3. Get an independent check if the seller can't provide one. Testing services plug a device into the car's diagnostic port.
4. Do a real-world range test. Charge to 100% if you can, and compare the range shown with the car's official figure, allowing for temperature.

What to ask the seller

• How was it mostly charged – at home, or on rapid chargers?
• Is there any battery warranty left, and does it transfer to you?
• Does it come with all its charging cables?
• For an older Renault Zoe: is the battery owned or leased?

Red flags

• The seller won't provide or allow a battery check
• Much lower range than you'd expect for its age
• A missing or patchy service history

Model guides

See our used EV guides for the Nissan Leaf, Renault Zoe, Tesla Model 3 and MG4.

General guidance only. Always check the specific car and its paperwork.