An Improved Algorithm of SOC Testing Based on Open-Circuit Voltage-Ampere Hour Method

An improved algorithm is proposed to estimate the SOC of the lithium-ion. Based on the combination of the open-circuit voltage and the Ampere-Hour integral measurements, aimed at the long standing time and error accumulation, improved the algorithm. Assessed manganese acid lithium battery, obtained the relationship between VOC and SOC and the optimal parameter, we can estimate the open-circuit voltage of the lithium battery in a short time by the model parameters, which greatly reduces the open circuit voltage method of incubation time. When charging or discharging the battery, compute the variation of the SOC through Ampere-Hour integral. Experiment confirmed the accuracy of the algorithm. This algorithm can accurately estimate the SOC thus has a certain reference value for the research of lithium battery management system.