How to Make an EV Battery Warranty Claim (UK)

First, work out whether you actually have a claim

Three things must all be true:

You're inside the time limit. Counted from first registration, not from your purchase.

You're inside the mileage limit. Whichever of the two runs out first ends the cover.

The battery is below the capacity threshold. Usually 70%. This is the one that catches people out. A pack at 73% has degraded badly but has no claim available, because it hasn't crossed the line.

If you're claiming for an outright fault rather than degradation, such as a dead module, a BMS failure, or a pack that won't charge, the capacity threshold doesn't apply. That falls under the defect side of the warranty instead, which is a different and generally more straightforward claim.

Get independent evidence first

This is the step most people skip, and it's the one that matters most.

Before you approach the dealer, get a documented battery health diagnostic from a qualified independent specialist. An IMI Level 3 or above technician can carry this out, typically for somewhere in the region of £80 to £150. What you want is a written report showing measured capacity against the original rated capacity.

Why bother, when the manufacturer will run their own test anyway? Because it changes the conversation. Walking in with third-party evidence that the pack is at 68% is a very different discussion to walking in saying the range feels worse than it used to. It also gives you something to fall back on if the dealer's own assessment comes back differently.

The claim process, step by step

1. Gather your paperwork. V5C, VIN, current mileage, full service history, and your independent diagnostic report.
2. Contact an approved dealer for the brand. Battery claims generally have to go through the manufacturer network, not an independent garage, even if an independent did your diagnostic.
3. Request a formal battery capacity assessment. The manufacturer runs their own diagnostic scan, measuring current capacity against the original specification using their own software. This is the reading that decides the claim.
4. Await the decision. If the measured capacity falls below the threshold within the time and mileage limits, the manufacturer authorises repair or replacement.
5. Confirm what's being replaced. Many faults are confined to individual modules rather than the whole pack. A module-level repair under warranty is still a valid outcome, not a fobbing-off, provided it restores capacity properly.

If your claim is refused

Refusals usually come down to one of a few reasons, and each has a different response:

"Capacity is above the threshold." If your independent report disagrees with theirs, say so and ask for the discrepancy to be explained. Diagnostic readings can vary depending on method and conditions.

"The vehicle wasn't serviced to schedule." Produce your records. If an independent did the work, evidence of their qualifications and approved parts matters here.

"This is an excluded cause." Ask which exclusion specifically, and check it against the warranty booklet wording rather than accepting a general statement.

"The warranty doesn't transfer." Rare on full EVs, but real on some plug-in hybrids. Check the booklet.

If you can't resolve it with the dealer, escalate to the manufacturer's UK customer service, and then to the Motor Ombudsman if the manufacturer subscribes to their scheme. Keep everything in writing throughout.

Worth knowing before you start

Manufacturers replace batteries far less often than public anxiety suggests. Analysis of large tracked EV fleets puts the real-world replacement rate at a low single-digit percentage, concentrated heavily in early first-generation cars. If your battery is genuinely below threshold, you're in an unusual position, and it's worth pursuing properly rather than assuming it's a lost cause.