There are lots of posts on social media claiming that EV batteries need to be replaced after five, or even three years.

Of course, this is complete nonsense. 

The first EV I owned was a ten year old Nissan Leaf 24kW.  You can read a mini review on the car elsewhere on my website. 

I bought it when it was already ten years old, as an interim vehicle in between my old diesel 4x4 and the EV I now use as a private hire vehicle.  As an early Leaf, it did not have the advancements of more modern EVs and so was more prone to suffering from depletion.  After 10 years of life charge cycles, in its old home on Jersey, the battery had lost a third of its ‘health’.  So, effectively, it was just a 16kW Leaf.  I still used it to drive my girlfriend to and from work.  I used it to go shopping in nearby towns and cities.  And I used it to take my girlfriend for a hair appointment that was right on the edge of the car’s range. 

It still worked. 

I guess that the reason so many people are willing to believe bad things about EV batteries, is because they’re used to the batteries in their smart phones depleting and becoming virtually useless. 

The thing is, the batteries in EVs, even the early ones, have active battery management.  EVs charge in a much smarter fashion, only replenishing depleted cells, which distributes the load across many thousands of cells that make up the whole pack. 

What about the guarantees

EVs come with extremely long guarantees, typically at least eight years and as much as 100,000 miles. 

Car manufacturers would not offer such guarantees if they were not confident in the cars, or more importantly the batteries, being able to deliver. 

The car manufacturers have delivered on the promises of the warranties, multiple times. 

One example of this would be the Model S Tesla used by a Californian taxi business, which has so far covered over 400,000 miles.  During that 643,738 km, the HV battery (the one that powers the car’s electric motors) was replaced twice.  The first time was at 194,000 miles, which it covered in just over two years.  The car had been repeatedly charged to 100% from a low state of charge, multiple times a day, against the advice from Tesla.  And yet they still swapped the battery under the warranty. The battery degradation was just 6%; not too bad for a car that had done such mileage. 

But, the second battery didn’t fare as well. 

Tesla replaced the battery again after a further 130,000 miles, which the Model S had completed in a matter of months,  This time the depletion was worse, at 22%.  The diagnostic checks showed there was an issue and so Tesla replaced the HV battery again and did some firmware updates to try and ensure better performance going forward.