When it comes to full electric cars. Unless the prices go way down on batteries. People will probably just send the car to the wrecker when it needs new batteries. Even if we hit the optimistic mark of $100 per kilowatt. A 75KW Tesla would cost $7,500. That's a lot of money to put into a car which is over 8 years old or over 100,000 miles (warranty length Model 3).
Right now, the estimate I found with a cursory search. Shows batteries run about $200 per kilowatt. I certainly can't see anyone dropping $15,000 on a car that old or worn. If prices don't drop.
People predicted the same thing when the Toyota Prius first hit the market. When the battery pack wore out, critics said that the cars, even if perfect condition, would all be "totaled" because the cost of the battery pack would far exceed the value of the car. But enough time has gone by that the first generation Prius is now old enough for us to know what has happened, and the prediction isn't true.
The two things we've found are that (A) almost nobody has to replace the battery packs because the cars simply don't have noticeable performance degradation. For example
Consumer Reports tested this old Prius with nearly a quarter million miles on it and found little degradation. (B) Even if you do need to replace the battery pack, the costs have come down enormously. The full MSRP price from Toyota for a first gen Prius battery pack is $3649, plus you get a "core charge" rebate back from the old pack of $1350, for a total cost of $2300. If you adjust that for inflation back to 2001, that's about $1600. IIRC, the critics were predicting costs up to $6000.
Teslas are quite different from the first gen Prius, being Lithium and all-electric. But the data so far is looking quite good:
Basically, even at 200,000km (124,000 miles) you still have 94% range. I don't know how much Tesla "overprovisions" their batteries, if at all, but even a tiny little bit of overprovisioning would effectively neutralize such a small range loss. Interestingly enough, most of the degradation happens early anyway, and sort of "plateaus out".
So this is sort of like the Prius "A" scenario above, where you don't really need to replace the battery packs in the first place.
