US Patent 7948207 Refuelable battery-powered electric vehicle

The electrical vehicle energy storage system permits the electric refueling of the electric vehicle just like an automobile would be refueled with gasoline at a gas station. Circuitry on board the vehicle accessible by the electric refueling station enables the determination of the energy content of the battery module or modules returned to the electric refueling station and the owner of the vehicle is given credit for the energy remaining in the battery module or modules which have been exchanged. Selective refueling may take place for given battery modules by removing them from the battery system and charging them at home, office or factory. A process for operating an electric vehicle is also disclosed and claimed.