I think the problem is that it would create a new form of range anxiety: what if you want to take a spontaneous trip and your car is at 20%? The other problem i

I think the problem is that it would create a new form of range anxiety: what if you want to take a spontaneous trip and your car is at 20%? The other problem is fear of degrading battery capacity through lots of cycles. In time, both of these could be solved, but for now, they're valid concerns that haven't been disproven.