“Be careful what you wish for.”
In daily use a car might need a range of 20 to 50 miles.
A car-mountable battery pack could both supply solar electricity for a family home when the sun doesn’t shine brightly as well as providing the range the family car might need for a recreational trip.
The car-mountable battery pack could easily be swapped for another at a former gas station.
The car-mountable battery would also be used to charge up the car’s built-in battery.