Battery system is a simple and widely used electrical energy storage system for industry, UPS, intelligent applications, vehicles, electrical appliances and others. It can drive the integration of the vehicle and the power grid. In high power applications, the battery is joint in series to enhance the potential and joint in parallel to increase the current, but because of the processing conditions of the battery and the imbalance between each cell, the total power is reduced. One of the most common balancing methods used today is passive balancing, which is based on the principle that a power resistor incorporated in series discharges the excess when one of the cells reaches the voltage or charge threshold so that the other cells can be charged. The present project intends to propose a solar power to balance the battery of an electric vehicle. There are three approaches of process: the first is solar balancing, which uses solar energy to charge the accumulator according to the lowest state of charge (SOC) while driving, the second refers to the energy stored in the memory cell which is delivered via the DC-DC converter to the accumulator cell with the lowest SOC, and the third is charging according to the altitude SOC when the vehicle is charging from an outlet and is parked. For the simulation, it has been used a battery pack with four 13.8 V Etch One, batteries connected in series. Conformable to the results of simulation, the proposed method can economize 1.465% to 1.904% of a 50 Ah battery pack total capacity every 13.2 km. The accumulator pack can be balanced when the solar current is about 6–7 A. The balancing remains very successful even if the solar current is reduced to 2–3 A or if the cell storage mode is used with the identical current limitation.