IMO what is needed is a standardized battery system and a short range emergency battery you can carry in the trunk with say- 30-40 mile range like what you have left in the tank when the "low fuel" light comes on.
Once they get to standardize all cars will use a drop in charged battery.
Pull up switch and go. Just like gas cars mileage will be determined by your power drain..
It's all about the money. Just like bank cards were back in the day. All the money boys fighting for position on who's system will be used.
