Estimating the state of charge on lead acid battery using the open circuit voltage method

Abstract

This research investigates one of the methods to estimate the State of Charge (SoC) of a lead-acid battery with an Open Circuit Voltage (OCV) method. Determining the battery voltage in open circuit condition with standard temperature (25oC). Observing the OCV of the battery on the discharging cycle then compare with the increasing and decreasing of the battery voltage in open circuit condition (OCV) that can show the SoC battery to determine the capacity of the battery. Then using the Coulomb Counting method to compare the estimated SoC by OCV method. The result shows that there is a different value measured by these two methods at the early and later stages during the discharge cycle of a lead-acid battery.