How long do electric car batteries last?
Most EV batteries are designed to last many years, and manufacturer warranties commonly cover battery degradation for around 8 years.
How EV batteries degrade
Like a phone battery, an EV battery slowly holds less energy as it ages and is used. The car's battery management system controls temperature and charging to slow this down.
How much capacity can a battery lose?
- Degradation is normally gradual.
- Losing some capacity does not mean the battery has failed.
- Reduced capacity mainly means less driving range.
EV battery warranties
Battery warranties usually cover a set number of years or miles, whichever comes first, and often a minimum capacity the battery must keep. Check the warranty booklet for your exact car.
Battery warranty benchmark
To qualify for the UK Electric Car Grant, cars must show battery performance of at least 80% of initial rated capacity after 3 years, and at least 70% after 8 years or 100,000 miles, whichever comes first. This is a useful yardstick, not a promise that applies to every car.
Does rapid charging damage the battery?
Repeated high-power charging can add some stress to a battery, but modern cars manage battery temperature and limit charging power to protect it. Occasional or regular rapid charging on journeys is what the cars are designed for.
Should I charge to 80%?
Many manufacturers recommend an everyday limit below 100% for some battery types, but guidance differs by car and battery chemistry. Some batteries are fine to charge to 100% regularly. Follow your car's manual or app.
What affects battery degradation?
- Age: batteries age even when not driven much.
- High temperatures: heat speeds up ageing.
- Staying very full or very empty for long periods.
- Charging behaviour: how often and how fast.
- Battery chemistry: different types age differently.
- The car's battery management system, which protects the battery.
Buying a used EV
- Battery state of health report, if available
- How much battery warranty is left
- Range shown when fully charged
- Charging performance on a test charge
- Recall and service history
Battery replacement
Full battery replacement is relatively uncommon. Sometimes individual modules or parts can be repaired instead. Replacement costs vary enormously between cars, so ask the manufacturer or a specialist for a quote for your model.