Which? study reveals EVs lose just 1% of range per year
A recent study by Which? has found that electric vehicle battery degradation is not as severe as drivers considering the switch from ICE to EV may expect.
As part of its annual car reliability survey, the consumer title questioned 3,595 EV owners, who reported how much range their all-electric car now has compared to when they first purchased it.
The survey found that, over the course of seven years, EVs lost an average of 1% of range per year.
Cars registered from 2023-24 displayed an average remaining range of 97%, and vehicles registered between 2021 and 2022 also returned an average remaining range of 97%.
Those registered from 2019-20 had a slightly lesser range of 96%, while those registered from 2017-18 had an average remaining range of 93%. Given all-electric vehicles around seven years old experience a 7% drop in range, then there is an average year-on-year reduction of 1%.
The average mileage covered by those who answered the survey was 6,001 miles – slightly below the national average – but it is the frequency and type of charging that is believed to have the greatest impact on battery life.
The findings from Which? are not the first time that myths surrounding EV battery life have been busted. In 2024, a Geotab analysis of 5,000 EVs showed that degradation was less than 2% per year and becoming less of an issue as battery technology improves. It found that average battery health improved has by 22% since 2019.
“With these higher levels of sustained health, batteries in the latest EV models will comfortably outlast the usable life of the vehicle and will likely not need to be replaced,” said David Savage, vice president for the UK and Ireland at Geotab.
“However, we still see battery reliability being used as a stick to beat EVs with. Hopefully, data like ours can finally put these myths to bed.
“The fact is that a 1.8% decline in battery health is unlikely to have a significant impact on most driver’s daily vehicle needs, and this number will only come down further with new EV models and improved battery technology.
“People should feel confident that many current EVs are suitable and cost-effective to replace a range of light, medium and heavy-duty ICE vehicles.”
In practice, a 1.8% per year drop in state of charge means a car like a Kia Niro EV with a 64.8kWh battery and 285-mile official range will lose 47.3 miles of range over a decade.
Battery longevity is frequently used by the anti-EV lobby to suggest EVs aren’t as durable as petrol or diesel cars. This claim is made despite most EV makers guaranteeing their batteries for far longer than any ICE powertrain component.
Most offer a seven- or eight- year warranty, while Toyota and Lexus guarantee their EV batteries will retain 90% of their capacity after 10 years or 620,000 miles.
