Development of voltage balancing method for series connected batteries by combination of switched capacitor and modified shunting resistor methods with series connected diodes

This paper proposes an alternative technique to develop battery voltage balancing methods based on the switched capacitor (SC) method by adding a modified switched shunting resistor method with the addition of several series connected diodes. The proposed technique was evaluated and compared to conventional SC method by simulation using Scilab 6.0 software, then validated based on experimental results. The simulation results show that the proposed method has better balancing speed than conventional SC method in all scenarios, in all level state of charge (SOC) variations, either in the bottom level, the middle level, or in the top level. The balancing speed of the proposed method can be increased through proper optimization on the control of the on-off duration in shunting resistor switch. Setting on duration 800 ms and off duration 200 ms can provide a fairly rapid balancing effect without excessive temperature rise, 50 ° C in maximum from the initial 25 ° C. Thus, the balancing method with this technique deserves to be developed further into an alternative method in developing battery balancing methods.