Why the Battery Matters More Than the Mileage

On a petrol or diesel car, a high mileage figure is usually the first thing that gives you pause. With an electric car, the picture is different. Electric motors and drivetrains are robust, and plenty of EVs shrug off 100,000 miles with very little drama. The component that genuinely ages is the battery pack, and its condition decides both the range you'll enjoy and what the car will be worth when you come to sell it.

That means two outwardly identical cars with the same mileage can behave very differently. One might still deliver close to its original range; the other might be noticeably down on capacity. The difference usually comes down to how the car was charged, how it was stored, and the climate it lived in. A proper battery health check should therefore sit at the very top of your list — above paintwork, above alloy wheels, above everything.

Get a Proper Battery Health Check

Ask the seller for a state of health (SoH) report produced by a main dealer or an independent EV specialist using diagnostic software. This is not the same as a photo of the dashboard showing the estimated range, which is little more than an educated guess based on recent driving. SoH tells you what percentage of the original usable capacity is still there.

As a rough guide, a three-year-old car in good order should still be in the low-to-mid nineties. Anything below 85 per cent deserves probing questions, and packs that drop towards 70 to 80 per cent may be nearing the manufacturer's warranty threshold. When you look at a report, dig into the detail:

• Cell balance: a healthy pack has its cells sitting within a narrow voltage range of one another. Big imbalances suggest trouble ahead.
• Rapid-charging history: frequent DC fast charging, especially on earlier air-cooled packs, speeds up degradation.
• Charge cycles: ask whether the car has spent long periods parked at very low or permanently at 100 per cent charge.
• Thermal management: liquid-cooled packs generally hold up better over time than early air-cooled designs.

Service History, Recalls and Software

Electric cars need less routine maintenance, but "less" is not "none". Brake fluid, coolant, cabin filters and tyres all still need attention, and brake calipers can seize on cars that rely heavily on regenerative braking. Ask to see the full service record and check the date of the last inspection rather than assuming a stamp in the book tells the whole story.

Software matters just as much. Many EVs receive over-the-air updates that improve charging speed, range estimates, thermal behaviour and infotainment. Confirm the car is running current software and that any dealer-applied campaigns or safety recalls have been completed. An outstanding recall isn't necessarily a deal-breaker, but it is a job you'll want done before you take the keys.

Charging: Cables, Connectors and Speeds

Charging hardware is easy to overlook and expensive to replace. Check the following before you agree a price:

• The cables: a Type 2 charging cable for public and home wallboxes, plus the emergency three-pin cable if it was originally supplied. Replacements add up quickly.
• Rapid-charging capability: confirm whether the car accepts CCS or CHAdeMO, and how quickly it actually charges in practice.
• Onboard charger rating: a 7kW unit is fine for overnight charging; an 11kW unit fills the battery faster if your home supply supports it.
• Charging port condition: inspect closely for scorching, bent pins, cracked housings or water ingress.

Also think honestly about your own parking. If you can't charge at home or at work, the ownership experience changes dramatically — you'll be relying on public networks, paying higher rates and planning journeys around chargers rather than around your day.

Warranty, Paperwork and Running Costs

Most manufacturers offer a separate battery warranty, commonly eight years or around 100,000 miles, and these are usually transferable to a new owner. Get the terms in writing. Find out what percentage of capacity triggers a replacement, whether the remedy is a repair or a reconditioned pack, and whether there's a fair wear-and-tear exclusion. Out-of-warranty battery replacement can run into several thousand pounds, so it's worth knowing where you stand.

Beyond that, check the V5C, the number of previous owners, the finance status through an independent history check, and the MOT record. Be aware that electric cars registered from April 2025 pay vehicle excise duty, and newer, pricier models can attract the expensive car supplement. Insurance quotes can also be higher than expected for certain models, so get a quote before you commit rather than after.

What to Test on the Drive

EVs are quiet, which is a gift when you're inspecting one: any whine, clonk or hum from the drivetrain stands out immediately. Use the test drive properly:

• Real range: reset the trip computer, note the state of charge, and drive a mix of town and faster roads. Cold weather cuts range noticeably, so a winter test is especially revealing.
• Heating and air conditioning: run both at full power. A failed heat pump or heater matrix is a costly repair.
• The 12-volt battery: a surprising number of EV breakdowns trace back to this small conventional battery, not the traction pack. Ask when it was last replaced.
• Tyres: instant torque punishes cheap rubber and poor alignment, so check for uneven wear across all four.

Ask for the battery report before you travel to view the car, take your time on the drive, and don't be shy about walking away. A well-chosen used electric car can be a brilliant, cheap-to-run companion for years. The careful homework is what gets you there.