Used EV shoppers usually fixate on one nightmare scenario. What if the battery is already worn out? A new UK industry report suggests that fear is often bigger than the problem.
Generational’s 2025 Battery Performance Index, based on more than 8,000 battery health assessments carried out in 2025, found an average battery health score of 95.15% across the vehicles it tested. The sample covered 36 makes, model years from 2013 to 2025, and mileages from zero to more than 160,000 miles.
Age matters, but not the way people think
In practical terms, many used EVs are holding on to much more of their original range than buyers may expect. Vehicles between two and three years old posted median battery health of 96.94%. Three-to-four year old models came in at 95.17%.
Even the eight-to-twelve year group held a median 85.04%, still comfortably above the 70% level where many manufacturer battery warranties are usually triggered.
That does not mean every used EV is a safe bet. The same report shows the spread gets wider as cars age. In the four-to-five year group, median battery health was 93.53%, but the lowest-performing 1% fell to 80.76%. So yes, problem cases exist. They just do not appear to be the norm.
The odometer is not the whole story
This may be the finding that hits buyers hardest. Mileage alone is not telling the full story. Generational found that EVs with more than 100,000 miles often still returned between 88% and 95% battery health, and it noted that a well-kept three-year-old ex-fleet car with 90,000 miles could be a better buy than a six-year-old car with just 30,000 miles.
Usage and charging behavior matter more than many people assume. For anyone thinking about the daily commute, grocery runs, or a lower-cost way into electric driving, that is a big shift.
What this means for the used market
Generational’s core conclusion is that battery degradation is “not the systemic risk it was once assumed to be.” It argues that uncertainty around battery condition, more than widespread battery failure, is what is dragging on resale values and buyer confidence. In practical terms, that means a battery health certificate may soon matter almost as much as service history.
At the end of the day, the message is simple. If you are shopping for a used EV, especially one under five years old, the smartest first question may no longer be “How many miles?” It may be “Has the battery been tested?”
The study was published by Generational.
