1 point
The enginnering part is for sure one of the reasons we don’t see that idea in the wild (yet?).
The fire hazard at home and degradation when stored full or empty (speaking of lithion ion based batteries here) go away if you lean on the rental approach.
Wouldn’t it be nice to save investment and weight by using the required amount of battery capacity while still being able to extend the range of your car easily when needed?
