Mythbusting the world of EVs: do you need a new battery every few years?

MYTH: You’ll have to get a new battery in a few years

Many electric car doubters assume the battery will be dead after eight years, because that’s how long most of their guarantees last. They also say, well, their phone batteries lose about a fifth of their capacity after three years or so. Charged nightly, that’s 1,000 cycles. During which time the phone has got hot, and always been charged right to full capacity. Battery life depends on cycles and on abuse – extreme charging and temperature – not so much on time.

Electric car owners often just charge the battery up to about three-quarters for normal commuting, as it’s gentler. But let’s assume the worst. You have a car that starts life with 250 miles’ range, and give it 1,000 charge cycles. At the end it has fallen to 80 per cent of its original capacity, or 200 miles. So, knocking on for a quarter of a million miles total.

You might have heard stories of early Nissan Leafs having their batteries replaced. It has happened, albeit on the cottage industry scale, with batteries from low-mileage crashed cars being transplanted into intact high-milers. But of course early Leafs had an initial range of only 100 miles, so they needed charging two-and-a-half times as often as today’s cars. And let’s not forget they’re a decade old, and had first-generation batteries without liquid cooling.

So talk of the fragility and early death of batteries is not something I can get terribly worked up about.