Battery degradation has long been a major concern for the used electric vehicle (EV) market, shaping buyer hesitation, retailer caution, and conservative financing models. However, new evidence suggests these fears may be largely overstated.
According to the Generational 2025 Battery Performance Index, which analyzed over 8,000 electric cars and vans across the UK, EV batteries are performing significantly better than commonly assumed. On average, vehicles maintain 95.15% of their original battery capacity, while even cars and vans aged eight to nine years retain a median 85% state of health—well above the typical 70% threshold that triggers manufacturer warranties.
These findings indicate that, in most cases, an EV battery is likely to outlast the vehicle itself.
So why does uncertainty around EV battery health persist? The research points to variability between individual vehicles. While most batteries degrade gradually, differences in charging habits, driving patterns, climate exposure, and overall maintenance create a widening performance gap as vehicles age. For example, vehicles four to five years old show a median battery health of 93.53%, but some lower-performing units fall considerably below this benchmark.
Traditional indicators such as age and mileage—reliable for internal combustion vehicles—often fail to predict battery condition in EVs. High-mileage EVs, for instance, frequently retain 88% to 95% battery capacity, while some lightly used cars may show faster degradation. Without transparent data, market participants are forced to rely on worst-case assumptions, leading to discounted prices, conservative financing, and weakened residual values.
The solution, according to experts, is transparency. Verified battery health data should become as routine in vehicle transactions as mileage checks or service history. Greater transparency would allow the market to distinguish high-performing vehicles from outliers, benefiting the entire automotive ecosystem:
- Retailers could price vehicles more accurately and sell them faster.
- Fleets could optimize holding periods and remarketing strategies.
- Insurers and warranty providers could develop actuarial models based on real-world battery data rather than conservative assumptions.
- Policymakers could address perceived financial risks tied to battery failure.
Electric vehicles represent a generational shift in automotive technology. Early market perceptions, shaped by caution and uncertainty, are now being challenged by real-world performance data. Industry-wide adoption of battery health checks—potentially integrated into MOT inspections—could help align perception with reality, strengthen residual values, and accelerate the transition to electric mobility.
For years, myths about rapid battery degradation have slowed the used EV market. With verified data and a commitment to transparency, stakeholders can finally set the record straight and unlock the full potential of the UK’s EV sector.
