How long do the batteries last?

How fast do electric car batteries wear out, and what does an owner do when that happens?

By Will Dron on July 19, 2011 6:41 PM

This is difficult to say right now as the first production electric cars with lithium ion battery technology are still very new, but most people agree they will last at least eight years before they reach what is called the 'end of life' – Vauxhall even has an eight-year warranty on the battery in its Ampera.

But ‘end of life’ doesn’t mean the battery will stop working at that moment – ‘end of life’ is actually the point at which batteries reach 80% efficiency, so they'll still work pretty well for years after that. In fact, some Ford Ranger EVs from the late 1990s with less efficient lead acid and NiMH batteries are still going, nearly 15 years later.

Lithium ion should fare a lot better, which is just as well because a new battery is expensive right now – they’re the major reason electric cars cost so much to buy – but prices will fall as more electric cars hit the road. And Nissan says you're going to have to replace individual modules in the battery pack, rather than an entire battery, which will cost hundreds of £s rather than thousands (or tens of thousands, if some reports will have you believe). There's more on this in the following video from Nissan:

The intrinsic value of the batteries also means they will be in demand – Nissan has developed a system to turn LEAF batteries into electric storage devices at renewable power stations, meaning they'll have a second life after they come out of the car.

Renault has come up with a different solution altogether – the batteries on their electric cars are leased separately so they will simply replace it for you at the end of life, should you wish to keep the car.

Still concerned? It might help to equate the battery to a petrol or diesel engine. After eight years the engine is a bit old and tired, perhaps a bit smokey, and doesn't have the same horsepower it had when new. Would you refurbish it, replace it or just keep going?