Quick answer
Key takeaways
- A small, early capacity drop is normal, the curve then flattens.
- Roughly 1-2% loss a year is typical for a well-treated pack.
- Heat, frequent rapid charging and sitting at 100% speed degradation up.
- Judge a car on its own degradation estimate, not the model’s reputation.
How much do EV batteries degrade?
Lithium-ion EV batteries follow a fairly predictable pattern: a slightly faster loss of a few percent in the first year or two, then a long, slow decline. Large real-world studies of tens of thousands of EVs put the average at somewhere around 1-2% a year, which is why most cars are still returning 85-90% of their original range well past 100,000 miles.
Manufacturers back this up with warranties that promise the battery won't fall below about 70% capacity within 8 years or 100,000 miles, more on that in our EV battery warranty guide.
What's normal by age and mileage
As a rough guide for a well-treated, liquid-cooled EV:
| Age / mileage | Typical capacity remaining | Verdict |
|---|---|---|
| 1-2 years / under 20k | ~95%+ | Expected |
| 3-5 years / 30-60k | ~90% | Healthy |
| 6-8 years / 70-100k | ~85-88% | Normal |
| Any age, big range drop | Below warranty threshold | Investigate |
These are typical figures, air-cooled cars such as early Nissan Leafs degrade faster, and any individual car can differ. That's why the specific car's estimate matters more than the average.
What causes faster degradation
- Heat, the biggest enemy of a battery. Cars used in hot climates or without active cooling degrade faster.
- Frequent rapid charging, occasional rapids are fine; a life spent on 50kW+ chargers adds up.
- Sitting at 100% (or very low), batteries are happiest kept between roughly 20% and 80% for daily use.
- Passive (air) cooling, packs without liquid cooling manage heat less well, so charging history matters more.
Warning signs of a tired pack
Be cautious if a car's expected range now is well below what its age and mileage suggest, if a relatively young car has already lost a lot of range, or if the seller is vague about charging habits. A big gap between the original and current range is the clearest red flag.
How to check a specific car's degradation
The Used EV Check estimates the degradation of the exact car from its registration and mileage, alongside the expected real-world range now versus when new and the warranty remaining. It turns “EVs generally hold up well” into a number for the car you're actually looking at. Range data is powered by ClearWatt.
Range and battery-health figures are estimates modelled from real-world data and are shown for the specific vehicle in the Used EV Check. Range data is powered by ClearWatt. A battery-health grade is shown where a manufacturer test record exists, it is a comparative grade, not a measured state-of-health percentage.
Check a used EV before you buy
Enter a registration to see a used EV's battery health, real-world range now vs when new and remaining battery warranty, an instant report for £9.99.
Frequently asked questions
How much battery degradation is acceptable when buying a used EV?+
Do EV batteries suddenly fail?+
Does rapid charging ruin an EV battery?+
Can you estimate degradation without plugging into the car?+
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