Electric car batteries are degrading at an average of 2.3 percent per year. However, new data shows a reliance on high-power rapid charging can accelerate degradation rates compared to ‘low and slow’ charging.
The research from Geotab, a fleet data analytics firm, shows that mainly using DC rapid chargers above 100kW leads to battery degradation rates of up to 3.0 percent a year – roughly twice that of vehicles that largely use lower-power chargers.
It also found that EVs operating in hot countries experience battery degradation around 0.4 percent more quickly than those in milder climates.
Geotab’s analysis used battery health data from more than 22,700 EVs across 21 makes and models. The average annual battery degradation rate of 2.3 percent in 2025 compares to 1.8 percent in 2024.
‘The increase reflects changes in how EVs are being used, most notably a growing reliance on high-power DC fast charging,’ said the firm.
‘By understanding how batteries age under different charging, climate and utilisation conditions, [fleet] operators can better manage EV performance, protect battery health and make more informed decisions about charging strategy over the life of the vehicle.’
EV batteries ‘lasting well’
“EV battery health remains strong, even as vehicles are charged faster and deployed more intensively,” said Geotab’s sustainable mobility manager, Charlotte Argue.
“Our latest data shows that batteries are still lasting well beyond the replacement cycles most fleets plan for.
“What has changed is that charging behaviour now plays a much bigger role in how quickly batteries age.”
Interestingly, the data showed that vehicles regularly using a wider state of charge range – such as going from fully charged to nearly empty – did not show meaningfully higher degradation “unless they spent prolonged, habitual periods near full or near empty charge levels”.
All electric car batteries degrade, added Geotab. This is measured by a metric called ‘state of health’ (SOH). For example, a 60kWh battery operating at 80 percent SOH effectively behaves like a 48kWh battery.
‘Geotab data shows that while degradation rates vary by model, charging behaviour and usage patterns, the majority of modern EV batteries remain fit for purpose well beyond typical ownership and fleet replacement timelines.’
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