Since the introduction of the first electric cars, there have been concerns that batteries will wear out rapidly and be hugely expensive to replace. New research from vehicle telematics experts GeoTab shows that's just not the case.
What does the GeoTab research show?
GeoTab has been keeping an eye on battery lifespans for some years now, and its research in 2024 showed that batteries were degrading, on average, at a rate of 1.8 per cent per year. The latest update to that research shows that the figure now stands at 2.3 per cent, which is - obviously - worse, but needs to be taken in context. It means that a small EV, such as a Renault 5, will lose around 10km of overall range each year. A car with a larger battery, such as Volkswagen ID.4, would lose 14km, but that is from a total claimed range of 565km.
Is that bad?
No, it's actually quite good, and the data is robust as it comes from 22,700 electric cars, across 21 makes and models. It's also important to remember that other research, such as that carried out by Germany's ADAC organisation, shows that battery control systems can be upgraded over the air. ADAC put a Volkswagen ID.3 through four years and almost 200,000km of abuse, including lots of fast charging, and inclusive of software updates that liberated a little extra usable battery capacity, the net degradation was just 2.0 per cent over four years.
"EV battery health remains strong, even as vehicles are charged faster and deployed more intensively,” said Charlotte Argue, Senior Manager, Sustainable Mobility at Geotab. "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, giving operators an opportunity to manage long-term risk through smart charging strategies.”
What can I do to protect my battery?
The answer, according to GeoTab, is to charge slowly most of the time. While fast DC chargers are becoming more prevalent, GeoTab's numbers show that regularly fast-charging above 100kW of DC power can accelerate battery degradation to around 3.0 per cent per year. If you stick to primarily slower AC charging - and this is where having a home charger and off-street charging really comes into play - then average degradation falls to just 1.5 per cent per year.
GeoTab's work showed that climate has a smaller independent effect. Vehicles operating in hotter regions degraded around 0.4 per cent faster per year than those in mild climates.
The research also showed that it's fine to charge your battery to full on the regular, as long as you're using the power up. Degradation only increases meaningfully if you're frequently leaving the battery fully charged or almost totally depleted. High mileage accelerates battery ageing a little, but only by 0.8 per cent compared to vehicles with lower mileage.
"For fleets, the focus should be balance,” said Argue. "Using the lowest charging power that still meets operational needs can make a measurable difference to long-term battery health without limiting vehicle availability.”