> No, it is simply a maintenance issue. There are already plenty of those in motor vehicles, and people are well-trained to track and manage them.

In addition, car batteries have:

a) vastly better charge controllers than the cheap crap that's put in phones

b) better quality cells to start with, or at the very least higher QA standards

c) BETTER CHARGERS. Cheap cellphone chargers can kill the battery with their unclean power, especially when linked with cheap charge controllers in the phone.

d) better thermal management with cooling and (iirc) heating, compared with a cellphone battery that has to endure anything between double-degree negative temps in winter to +40 °C when it gets held by the user or the CPU gets active.