Your Rights When You Buy a Used EV With a Bad Battery
You bought a used electric car in good faith. A few weeks in, the range is nowhere near what you expected, the charging is slow, or a warning light has appeared. It is a horrible feeling, and the first question most people ask is a fair one: where do I stand?
The good news is that if you bought from a UK dealer or trader, the law gives you real protection. This guide walks through your rights in plain English, what "faulty" actually means for a battery, and the practical steps to take if things go wrong. It is general information rather than legal advice, but it should help you understand where you stand and what to do next.
Who this applies to
Your strongest rights come from the Consumer Rights Act 2015, and they apply when you buy from a business: a dealer, a franchise, or a trader. That covers most used car forecourts and many online sellers.
Buying privately, from another individual, is different. Private sales are covered by far weaker rules, mostly that the car must be "as described." There is no requirement of satisfactory quality from a private seller, which is one reason a battery check before you buy matters so much.
What counts as a faulty battery
Under the Consumer Rights Act, goods you buy from a trader must be of satisfactory quality, fit for purpose, and as described. That includes durability, and it very much includes the battery.
A battery does not have to be completely dead to be a problem. It may fall short if:
- Its real-world range is far below what a reasonable buyer would expect for the car's age and mileage
- Its state of health is well below normal for the model and has clearly declined faster than it should
- It was described as being in a certain condition that turns out not to be true
- There is a genuine fault, such as a failing module or a battery management issue, not just ordinary wear
The tricky part is that some decline is completely normal. EV batteries lose a little capacity in the first year and then settle into a slow, gradual decline. Knowing the difference between normal ageing and an actual fault is where independent evidence becomes so valuable, and it is why a single dashboard percentage can be misleading. For more on that, see state of health explained: why readings vary.
Your two main rights
The 30-day short-term right to reject
For the first 30 days after you take ownership, if the car is faulty you have a short-term right to reject it and get a full refund. This is one of the strongest consumer rights there is. The clock starts from delivery, so if something is clearly wrong with the battery, do not sit on it. Report it quickly and in writing.
The 6-month rule: the burden is on the dealer
This is the part most buyers do not know about, and it matters enormously with batteries.
Under the Consumer Rights Act 2015, section 19(14), for the first six months after sale, if a fault appears it is presumed to have been present at the point of sale. In plain terms, you do not have to prove the battery was already faulty when you bought it. The dealer has to prove it was not.
After that first 30-day window, if the fault is confirmed the dealer usually gets one opportunity to repair or replace before you can move to a refund, which may be reduced to reflect the use you have had. Beyond six months the burden flips, and it becomes your job to show the fault was there at sale, which is much harder without evidence.
Why evidence of condition matters to both sides
Here is the honest reality of a battery dispute: it often comes down to one word against another. You say the battery was failing when you bought it. The dealer says it was fine and you must have caused the problem. Without solid data, these arguments drag on, and they are stressful and expensive for everyone.
That is why an independent record of the battery's condition at the point of sale is so powerful. It protects you, because it shows what you were actually sold. And it protects a good dealer too, because it shows the car left the forecourt in the condition they claimed.
This is exactly why we always recommend an independent battery health check rather than relying on a dashboard readout or a seller's word. A proper test looks at the battery cell by cell and produces a TÜV Certified certificate with the real state of health. If you have that from day one, a dispute is far less likely to happen at all, and far easier to resolve if it does.
The cost of getting it wrong
Battery disputes are not small. The average EV battery dispute claim now sits at £6,193 (Motor Ombudsman, Q4 2025), and a full battery replacement can run from £12,000 to £25,000 or more. Those numbers explain why buyers increasingly want proof before they commit. In fact, 88% of used EV buyers say they want an independent battery health assessment before buying (Startline Motor Finance Used Car Tracker, August 2025).
Given the sums involved, spending a little to confirm the battery's health, before or soon after purchase, is a sensible move.
What to do if your battery is faulty
If you suspect a real problem, work through these steps calmly and keep a record of everything.
- Act quickly. Note the date you took delivery. The 30-day and 6-month windows both matter, so do not delay.
- Put it in writing. Email or message the dealer describing the problem clearly. A paper trail is your friend.
- Gather evidence. Charge logs, range readings, dashboard messages, photos. An independent battery health test that shows the current state of health is some of the strongest evidence you can have.
- Give the dealer a fair chance to respond. The law expects a reasonable process. Being clear and reasonable also strengthens your position if it escalates.
- Escalate if needed. Many reputable dealers belong to an alternative dispute resolution scheme such as the Motor Ombudsman. If you cannot reach agreement, that route, or ultimately the courts, is available.
For a fuller look at how the law works from the trade's side, which is useful to understand what a dealer is thinking, see Consumer Rights Act: used EV battery liability.
The simplest protection is prevention
Nearly every battery dispute traces back to the same gap: nobody actually knew the battery's true condition at the point of sale. Fix that gap and most of the risk disappears.
If you are buying, get an independent check before you hand over the money. If you have just bought and something feels off, get one now while you are still well inside the six-month window. Either way, an independent, cell-level battery report gives you the facts to stand on.
A £100 certified battery health check gives you a clear, independent record of exactly what you own, and the confidence to act on it if you ever need to.