Buying a used electric car: what to check

A used electric car can be a superb buy: cheaper to run, quiet, and often heavily depreciated in the first few years. But EVs come with a few checks petrol and diesel buyers never had to think about — chief among them, the health of the battery. Here is what to inspect before you hand over any money.

Battery health comes first

On an EV, the traction battery is the single most valuable component — replacing one out of warranty can cost more than the car is worth. That makes state of health (SoH) the most important number in the whole transaction. SoH describes how much of the battery's original usable capacity remains after years of charging and discharging. A car with a healthy battery will deliver close to its original range; one with a tired battery will fall short, no matter how clean the bodywork looks.

All lithium-ion batteries degrade gradually with age and use, and the rate depends on climate, how the car was charged and how hard it was driven. The key point for a buyer is simple: you cannot judge battery health by looking at the car, and two identical models of the same age can be in very different condition.

How to check battery health

There are three practical ways to get a read on SoH, and it is wise to use more than one:

• Manufacturer battery report. Some brands and franchised dealers can pull an official battery health certificate from the car's systems. If one is offered, ask for it in writing and note the date.
• In-car readouts. Many EVs show battery details in the settings or service menus, and some display predicted range at full charge. Charge the car to 100% before viewing and compare the figure against the model's original range.
• Independent battery test. A growing number of specialists and diagnostic tools can measure SoH directly through the car's data port. For an expensive purchase this is money well spent, as it gives an impartial figure the seller cannot massage.

Real-world range vs the claimed figure

The official range on the advert is a laboratory number. Real-world range is almost always lower, and the gap widens in cold weather, at motorway speeds, and with the heating running. When you view the car, note the indicated range at a known charge level and treat the manufacturer's headline figure as a best case rather than a promise. If your daily journeys are long, be honest about whether the car's genuine range covers them with a comfortable margin.

Charging: connectors, speed and cables

Charging is where used EV buyers most often get caught out, so check the practicalities carefully.

Connector types

Most modern EVs sold in the UK use a Type 2 connector for AC (home and destination) charging and CCS for rapid DC charging, but some older or imported models use different standards. Confirm the car takes the connectors used by the public networks you rely on, and by any home charger you already own.

Home charging and charge speed

If you can charge at home, that is where an EV saves you the most, so consider whether you have off-street parking and a wallbox, or plan to install one. Ask how quickly the car accepts a charge, both on a home wallbox and on a rapid charger — maximum charging speed varies a lot between models and directly affects how convenient longer trips will be.

Cables included

Charging cables are expensive to replace, so confirm exactly what comes with the car. Ideally you want both a Type 2 cable for public and home AC points and, where supplied, a three-pin granny cable for occasional top-ups. Check the cables for damaged pins or melted casing while you are at it.

Battery warranty transfer

Most manufacturers provide a separate, longer warranty on the traction battery than on the rest of the car, typically guaranteeing it against failure and against dropping below a stated capacity within a set period or mileage. On a used EV this warranty is valuable, but only if it transfers to you. Ask for the original registration date, check how much of the battery warranty remains, and confirm with the manufacturer that it carries over to a new owner. A car still inside its battery warranty carries far less risk than one just outside it.

The usual provenance checks still apply

An EV is still a used car, so every history check you would run on a petrol model matters just as much here. Before you commit, make sure the vehicle is not on outstanding finance, has not been recorded as an insurance write-off, is not listed as stolen, and that the recorded mileage is consistent. See what we check for the full list. Mileage still matters on an EV too — not only for wear on tyres, brakes and suspension, but as a rough guide to how hard the battery has worked.

Tax and clean-air zone benefits

Running an EV comes with genuine cost advantages. Electric cars are generally exempt from the charges levied by clean-air and ultra-low emission zones such as ULEZ, which can save frequent city drivers a substantial sum over a year. Company-car drivers have historically paid much lower benefit-in-kind tax on EVs than on petrol or diesel equivalents. Vehicle tax rules do change over time, so confirm the current position for the specific car before you rely on any saving.

What a written-off or flood-damaged EV means

A write-off carries an extra dimension on an electric car. Because the battery sits low in the floor of the vehicle, structural damage, fire or flooding can compromise the battery pack and its high-voltage wiring — and damage there is not always visible. Water ingress in particular is a serious concern for a high-voltage system. If a history check flags an EV as a former write-off, or you suspect flood damage, treat it with real caution and insist on an inspection by someone qualified to assess the battery and electrical system, not just the panels.

The bottom line

A used EV can be one of the smartest car purchases you make, provided you check the things that are unique to electric cars: battery health, honest real-world range, charging compatibility and a transferable battery warranty. Layer the standard history checks on top, walk away from anything with an unexplained write-off, and you can buy with confidence.