An electronic system in a vehicle includes a motor, a charger, a battery pack, and a bus. The motor drives wheels and propellers of the vehicle. The charger generates charging power according to a control signal. The battery pack coupled to the charger and the motor is operable for generating the control signal based upon a status of each cell of multiple cells in the battery pack, for receiving the charging power via a charging path when the vehicle is stalled, and for powering the motor via a discharging path when the vehicle is started. The bus coupled to the charger and the battery pack is operable for transmitting the control signal from the battery pack to the charger.