The working principle is to charge the photovoltaic electricity to the car through the control device, such as photovoltaic electricity is rich, or through the energy storage battery pack to store the electricity, or return to the grid; such as photovoltaic electricity is insufficient, and then join the grid through the charging station's output device or will be the battery's power transmission to the electric car; for example, in the weather conditions of the poor solar power is not enough to supply the charging of the electric car, through the power grid power supply to the charging of the electric car.