EV Battery Warranty UK — What Does It Cover?

Standard UK EV battery warranty terms

Typical industry-standard cover:

• 8 years / 100,000 miles (whichever comes first)
• Guarantees at least 70% of original capacity at end of warranty
• Covers manufacturing defects + capacity loss
• Usually transfers to a second owner

Some brands are more generous:

• Tesla: 8 years / 100k–150k miles (depending on model), 70% retention
• Kia / Hyundai: 7 years / 100k miles
• Lexus: 10 years / 1,000,000 km with annual EV health check
• Renault / Dacia: 8 years / 100k miles, 70% retention

What's NOT covered

• Damage from accidents or physical impact
• Damage from flooding or submersion
• Use of non-approved chargers (mostly historical — modern Type 2 / CCS chargers are universal)
• Modifications (e.g. range-extender mods, third-party BMS)
• Capacity loss above the threshold (e.g. 75% — still bad, but not a warranty claim)

How to protect your warranty

• Service annually with an IMI-qualified technician — keep the digital record.
• Don't let the pack sit at 0% for extended periods. Most BMS systems shut off at 5–10% to protect cells, but prolonged deep discharge accelerates degradation.
• Limit habitual DC-fast-charging to 100% — Tesla and others advise charging to 80–90% for daily use, 100% only before long trips.
• Garage the car in extreme heat where possible.
• Keep documentation of any third-party repairs done on the HV system.

How to claim

If you suspect your battery is below the warranty threshold:

1. Get a battery health diagnostic from an IMI Level 3+ specialist — typically £80–£150.

2. Print the state-of-health report.

3. Contact the manufacturer or main dealer with the report.

4. They'll usually request their own diagnostic before authorising work.

Independent specialists listed on The EV Pros can carry out the initial diagnostic at a fraction of dealer rates.

FAQs