That (and the linked German release, as much as I can understand it) is a very interesting spin on lifespan, but without seeing the actual numbers it doesn't actually say a lot, other than "batteries aren't awful".
70% is Renault's (and other manufacturer's) common figure for "this battery needs to be replaced". For the smaller batteries which had (say) 150 mile range when new, that brings them down to just about 100 miles under ideal circumstances, and it seems also to be true that there comes a point where capacity stops dropping smoothly and things such as cell failures become common.
So while 100 miles might be an acceptable range for many people, given that that batter might be 9 years old, will it still have 90 miles range next year? Or will it just cough and die?
I suppose what I'm wondering is, how many of those cars which have reached 70% actually need a new battery at this point to be useful beyond popping down to the supermarket?
I've had a quick look, but I suspect the figures haven't been released, what would make that report most useful would be the following statistics:
- capacity at survey point against age of car
- capacity at survey point against mileage of car (I suspect this is the best indicator)
- data on battery performance between (say) 70% and 50% capacity, particularly whether the deterioration accelerates, or batteries suffer "failures" (i.e. making them unusable) after 70%
100,000 miles isn't terribly far these days, and I'm doing that in about four or five years myself. I've always kept cars a
lot longer than that!
M.