State of Charge (SoC) is a parameter used to determine the current capacity on a
battery as well as indicate the operational characteristics. The SoC is an
important parameter for optimizing battery utilization in many applications
requiring DC current source. However, estimating the SoC value is the major
problem since it cannot be measured directly. In this study, we proposed SoC
measurement method based on analysis internal resistance of battery. The
internal resistance is correlated with the parameters of the magnitude of the
terminal voltage and open circuit. Both voltages come from the influence of
current during the charging-discharging process. We report that the proposed
method has successfully obtained the correlation between the SoC and the
internal resistance value for two process, which are the charging- and
discharging process.
Keywords
Internal resistance, Open circuit voltage, Recovery effect, State of charge, Terminal voltage