Passive Balancing of Battery using Coulomb Counting and Kalman Filter based SoC Estimation

The balancing of a cell in a battery pack comprises of controlling the charging and discharging of the respective cell to keep it at the same potential as of the other cells in the battery pack. The paper describes the process of balancing a cell by taking the State of Charge (SoC) of the cell into consideration rather than the conventional voltage of the cell. The estimation of the SoC is done by applying Kalman Filter to the measurement. This usage of Kalman Filter helps in estimating the SoC very accurately and thus helping in balancing the cell more effectively and thereby improving the overall health of the battery pack.