How long do electric car batteries last? A lot longer than expected

Electric car batteries are lasting longer than expected, according to the largest-ever UK used EV battery study, conducted by battery health experts Generational.

The firm analysed 8,000 EVs across 36 manufacturers, aged between 0 and 12 years and ranging from 0 to more than 160,000 miles. Experts discovered that the average state of health (SoH) of the batteries, all ages considered, was 95 per cent – well above the 70 per cent usually stipulated by manufacturer warranties as the grounds for battery replacement.

In fact, even the oldest EVs, aged between eight and 12 years, showed a median battery SoH of 85 per cent; the lowest 25th percentile showed an average battery SoH of 82 per cent, while the best-maintained models of this age group still retained 90 per cent of their original capacity.

Generational’s CEO, Oliver Phillpott, said: “The data definitively shows that EV batteries are performing far better than many consumers and industry stakeholders have been led to believe. 

“With an average State of Health of more than 95 per cent, and even older vehicles comfortably exceeding warranty thresholds, the underlying fundamentals are extremely strong.”

One interesting learning point from the study is that a car’s mileage isn’t always an indicator of its battery’s SoH; Generational found that EV examples with much more than well over 100,000 miles on their clocks “frequently return 88-95 per cent battery health, challenging traditional age-and-mileage valuation models”.

The firm points out that a newer, higher-mileage model may provide a better option in terms of battery SoH than, say, a slightly older one with fewer miles on the odometer.

Ultimately, Generational’s study is perhaps one of our most enlightening first looks at battery degradation – something that has been the concern of many in the switch to EVs. The data should, in theory, allow insurers to provide a more accurate (and hopefully affordable) quote knowing the true lifespan of battery packs, while fleet operators should get a better idea of the total costs of ownership.

Generational believes, however, that things could go a step further by standardising battery condition reports in the form of battery passports. These would provide prospective used-EV buyers an insight into the SoH of a car they may be looking to purchase.

Philip Nothard, Chair of the Vehicle Remarketing Association, explained: “Potential buyers of used electric cars understandably place a huge emphasis on battery health. They need to trust that this fundamental and expensive vehicle component will meet their needs without any unpleasant surprises. Transparency will prove crucial in building future consumer confidence and dispelling the many misconceptions that have gained currency around EV batteries.”

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