A battery electric vehicle, comprising:
- a vehicle body having at least one driving wheel and at least one non-driving wheel, wherein the axle of the driving wheel is independent to and different from the axle of the non-driving wheel;
- an electric motor connected to the driving wheel through the axle of the driving wheel to drive the driving wheel rotating;
- an electric generator being independent of the electric motor, the electric generator connected to and driven by the non-driving wheel through the axle of the non-driving wheel such that the rotational kinetic energy of the non-driving wheel is converted by the electric generator into electrical energy and the non-driving wheel connected to the electric generator is different from the driving wheel connected to the electric motor;
- and
- an electricity management device including a management and controlling member, a detecting member, and a plurality of battery packs which store the electrical energy converted by the electric generator,
- wherein the management and controlling member electrically connects to the detecting member and the plurality of battery packs, the detecting member keeps detecting the electrical quantity of each battery pack to obtain a detecting result of each battery pack of the plurality of battery packs, the management and controlling member performs a selection from the plurality of battery packs according to the present detecting result of each battery pack of the plurality of battery packs to determine at least one selected battery pack as an electric supplying battery pack and at least one non-selected battery pack, as an electric charging battery pack, other than said at least one selected battery pack, the management and controlling member electrically connects the electric supplying battery pack to the electric motor, and the management and controlling member electrically connects the electric charging battery pack to the electric generator according to the detecting result in such a manner that an operation that the connected electric supplying battery pack provides electricity to the electric motor for driving the driving wheel and an operation that the connected electric charging battery pack stores the electrical energy converted from the rotational kinetic energy of the non-driving wheel by the electric generator are operated simultaneously according to the detecting result of each battery pack of the plurality of battery packs, the electric generator converts the rotational kinetic energy of the non-driving wheel into electrical energy and then the converted electrical energy is then transferred to the connected electric charging battery pack according to the detecting result of each battery pack of the plurality of battery packs.