A combined SOC estimation method under varied ambient temperature for a lead-acid battery

This paper describes a practical ambient temperature dependant battery state of charge (SOC) estimation algorithm that can determine the SOC of a battery operating under load conditions. SOC is an essential parameter in a monitoring system, which is the basis of a battery management system (BMS). Temperature has a profound effect on the actual capacity or SOC of the battery. The proposed model in this paper determines the SOC by incorporating the changes occurring to charge acceptance, power deliverable and internal resistance due to the variations in temperature.