On the Usage of Battery Equivalent Series Resistance for Shuntless Coulomb Counting and SOC Estimation

In this paper, a feasibility study of shuntless coulomb counting method for estimating the state charge (SOC) battery is presented. Contrary to conventional counting, proposed does not require an external resistive shunt; it instead only requires voltage measurements performed on under test while operating. The current measured indirectly using battery’s equivalent series resistance (ESR). consists preliminary calibration phase where ESR and open-circuit are different SOCs stored in look-up tables (LUTs). Then, subsequent operational phase, uses these LUTs together with at terminals estimate SOC. performance evaluated sample lithium polymer (LiPo) battery, realistic profile derived from Worldwide Harmonized Light-Duty Vehicles Test Procedure (WLTP). results experimental evaluation demonstrate SOC estimation root-mean-square error 0.82% maximum 1.45%. These prove that feasible practical scenario.