One of the biggest concerns among buyers is how long EV batteries last. It’s a fair point because EVs are a relatively new technology and all we have to fall back on is our experience with mobile phones and laptop computers. And let’s be honest, the batteries in those aren’t known for their longevity.
EV batteries are made up of many cells
The big difference between a mobile phone and an electric vehicle is that while a phone battery has one cell, the car’s battery is made up of hundreds of cells. This means that cell degradation over time is split across multiple cells so they lose performance relatively slowly.
EVs are clever
There are a number of things that cause batteries to degrade quickly. Excess heat from charging, being charged to the maximum and being run down until empty. Car makers have worked hard to ensure the heat generated during charging is carefully managed in modern EVs. That’s why when you plug your car in to charge, you might hear its cooling fans start whirring away.
The batteries in EVs are also managed by clever control systems. These ensure that the car switches off before the battery is fully drained, preventing damage to the cells.
Equally, although a car will tell you it’s charged to 100%, there’s actually more capacity in there that isn’t used. This is another strategy designed to preserve battery life.
But batteries are guaranteed
There are things owners can do to preserve a car’s battery life. Nonetheless, all that charging and discharging shortens batteries’ lifespan. Even so, the car makers guarantee them with a warranty for, in most cases, up to eight years or 100,000 miles, whichever comes first.
According to the RAC, independent research showed that an eight-year old Nissan Leaf had only lost 20% of its battery life. Meanwhile Tesla says its cars lose only 10% of their capacity after 200,000 miles.
The manufacturer warranties usually guarantee that after eight years, a car will still have at least 70% of its capacity left in it. That means if a car originally had a range of 250 miles it would still be good for 175 miles.
And manufacturers believe cars will outlast the batteries
Tesla says in Europe its batteries will last for 150,000 miles. Bear in mind that the average annual mileage for a car in the UK is around 8,000 miles and that’s nearly 19 years. The average age that cars in the UK shuffle off to the scrapheap is usually around 14 years.
There is a precedent
Although full EVs haven’t been around for all that long, electrified cars such as the Toyota Prius have. This is a self-charging hybrid which uses a lithium-ion battery powered motor to supplement the petrol engine.
And in the US, the Prius tops the list of cars that people hang onto the longest. There are still some models from the late 90s going strong.
Have you got anything to worry about? We think it’s unlikely. And if things do go wrong when your car’s out of warranty, you could always blow it up, like one frustrated Finnish owner did.
More seriously, if you’re buying a used EV and its warranty has lapsed, it’s definitely worthwhile having the battery checked out.
I’ve been writing about cars and motoring for more than 25 years. My career started on a long-departed classic car weekly magazine called AutoClassic. I’ve since pitched up at Autosport, Auto Express, the News of the World, Sunday Times and most recently the Daily Telegraph. When I’m not writing about cars and motoring, I’m probably doing some kind of sport or working in my garden.