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Used EV battery worse than described? Your rights in the UK

Published 2026-10-28 · Last updated 2026-10-28

You've bought a used electric car and the battery seems weaker than you were told: the range has dropped, a test shows a low state of health (SoH), or a warning light came on. This guide sets out the UK rules that apply, the time limits, who to complain to (including when the car is on finance), and why written battery evidence decides so many disputes. It covers England, Wales and Northern Ireland in outline. It is general information, not legal advice.

First: is it a fault, or normal ageing?

All lithium-ion batteries lose some capacity. Citizens Advice says you aren't entitled to anything for wear and tear that is normal for how much the car has been used, for a fault you were told about and that was fully explained, or for one you should have spotted when you inspected the car (Citizens Advice). The law asks whether the car's quality was what a reasonable person would consider satisfactory, taking account of its description, its price and all the other circumstances, including what was said in the advert (legislation.gov.uk).

• Get the battery measured. An independent test gives a dated SoH figure. An AVILOO certificate can be checked by QR code on AVILOO's website, and Generational's online certificate is the definitive version (AVILOO GmbH, Generational).
• Compare it with what's normal for the model. Use the model pages, the battery health estimator or the degradation chart. As a rule of thumb ADAC expects at least 92% at 50,000 km, 88% at 100,000 km, 84% at 150,000 km, 80% at 200,000 km (ADAC); 1,000 Generational battery checks at Shoreham Vehicle Auctions (UK used EVs, all models): average SoH 98.7% under 4 years (656 cars), 92.6% at 4–6 years (279 cars, 83.5% above 90%), 88.8% at 6+ years (73 cars, 34.3% above 90%); overall median 95.6%, 88% above 90%, and only 0.4% below 80% (all older Nissan Leaf and NV200 Combi) (Motor Trader).
• Check the advert and paperwork. A stated SoH, a range claim, "battery perfect" or "full battery warranty" are part of the description you can rely on.
• Check recalls and the manufacturer warranty. Unfixed safety recalls can be checked by registration on GOV.UK (GOV.UK); battery warranty terms by model are in our battery warranty checker. A battery under warranty may be the quickest fix.

Bought from a dealer: Consumer Rights Act 2015

The Consumer Rights Act has more conditions than this summary shows. Citizens Advice has a step-by-step tool for used-car problems (Citizens Advice); its advice differs for Scotland.

Bought on finance (hire purchase or conditional sale)

With hire purchase and conditional sale, the finance company is legally the supplier of the car and is responsible for its quality when supplied. The Financial Ombudsman says a used car isn't expected to be perfect, but a finance company may still be responsible for defects a reasonable person wouldn't expect at that price, age and mileage (Financial Ombudsman Service).

1. Complain in writing to the finance company (and the dealer), with the test result and the advert.
2. Most businesses have up to 8 weeks to respond (Financial Ombudsman Service).
3. If you disagree with the final response, or get none in time, you can take the complaint to the Financial Ombudsman. Do it within 6 months of the date on the final response (Financial Ombudsman Service).

Evidence matters at the ombudsman. MotorCheck's review of published decisions found 271 verified EV battery cases. In 49 of them, the presence or absence of a battery health certificate was the deciding factor, and 120 of 137 consumers who sought to reject an EV succeeded (MotorCheck Research). In one decision it quotes (DRN-5695390), a complaint involving £54,956 was not upheld because a vehicle health check from March 2025 had recorded no battery issues and there was no other evidence. MotorCheck sells vehicle checks, so treat its framing with care, but the cases it cites are public ombudsman decisions.

Bought from a private seller

Private sales have narrower rights. The car must match the description the seller gave (Sale of Goods Act 1979, section 13), and if it doesn't you can claim compensation, for example the difference in value (legislation.gov.uk, Citizens Advice). So a stated SoH or "battery like new" in a private advert matters; silence usually doesn't. Citizens Advice has a template letter for this (Citizens Advice).

The AVILOO battery warranty that comes with some UK tests

Battery Health Check, an AVILOO partner in the UK, says that from 1 July 2026 every qualifying paid AVILOO FLASH test in the UK includes the AVILOO Battery Warranty at no extra cost. It pays £2,700 if the battery falls below a threshold set for that car, within 12 months or 12,428 extra miles of the test, and allows one payout per vehicle (Battery Health Check, 2026-07-16).

AVILOO's terms add conditions worth knowing (AVILOO GmbH):

• It's a voluntary guarantee under Austrian law and does not affect your statutory rights. It sits alongside the rules above, not instead of them.
• Cover runs for 12 months or 20,000 km from the first test. It's tied to the VIN and passes automatically to a new owner with full legal title.
• It doesn't pass to anyone holding the car under a lease, hire purchase or another arrangement where someone else keeps the title. Many UK used EVs are bought that way, so check before relying on it.
• A claim needs a new validation test, and you must notify AVILOO within 14 calendar days of that test. Taxi, private-hire, ride-hailing and delivery use is excluded.

Evidence to gather

• The advert (screenshot it), the invoice, and any finance agreement.
• Any battery certificate from before the sale, and a new independent test now, with the date, mileage and verification link.
• Photos of warning lights and messages, and dates of charging or range problems.
• Written messages with the seller. Our questions-to-ask-the-seller checklist helps you get answers in writing before you buy.

This is general information, not legal advice. For advice on your situation, contact Citizens Advice, the Financial Ombudsman Service or a solicitor.

Also see: how to check a used EV battery before you buy · how to read a battery certificate · battery state of health (SoH) explained · EV battery replacement cost (UK) · selling an EV: proving battery health.

We are not paid by the battery-test providers mentioned on this page. Links marked "paid link" in the "Useful products and services" box are affiliate links. See our disclosure.

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