GREEN SPECIAL: What happens to BEV batteries when they wear down?
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One of the big questions surrounding the true sustainability of Battery Electric Vehicles (BEVs) is what happens when the battery packs degrade to the point where they are no longer practical to power the car.
Yes, batteries do wear out and retain less charge over time, just like petrol and diesel engines wear out as time and distance catches up with them.
Just like a petrol engine, the life of a BEV-battery will depend on how it’s used and cared for. But it’s likely that after 10-15 years a battery will be starting to show its age, giving reduced range.
So what happens then? As with any kind of vehicle, a BEV will be passed down through a cycle of owners as it gets older. A buyer paying a much smaller amount for a much older BEV will naturally accept that it will not have the same range as a brand new vehicle.
In modern BEV battery packs, individual cells (there are 130 in an Audi e-tron, for example) can be repaired or replaced, extending the life of the powertrain considerably.
But even once a battery gets to the point where it can no longer practicably power a vehicle, it could easily be destined for a “second life” storing household power.
There’s growing awareness of this potential around the world. It’s especially relevant when linked to the use of domestic solar panels. Solar panels collect sustainable electricity, but you can’t control when they’re doing their best work (that’s up to Mother Nature) and you won’t always be home to take advantage when they are. That solar power needs to be stored.
And lithium-ion batteries are the ideal vehicle (excuse the pun), not just for that sunny stuff but also to draw power off-peak for later use.
Domestic power flows are much more gentle than the massive surge required to power a BEV, so a battery that’s no longer capable of propelling a vehicle could still give years – or even decades – of service in a domestic environment.
Indeed, overseas some businesses are creating “stacks” of ex-BEV batteries (in shipping containers, for example) to power commercial premises. Rather than being unwanted waste, these lithium-ion units are currently very much in demand.
Even if they don’t find a second life, lithium batteries are much less toxic and much more recyclable than a traditional lead-acid unit. Over 90 per cent of the materials can be used and recycled time and time again, so it’s inevitable that a much larger industry will grow around end-of-life BEV batteries as they become more common in the vehicle fleet.