Patent ID: 8374807

Claim:
A method for estimating a state of charge (SOC) of a battery, comprising: generating one or more curves with a processor, the generated one or more curves expressing an a priori relationship between a first parameter and the SOC of a battery over a region of interest; taking a derivative with the processor of the generated one or more curves with respect to the SOC to generate a derived parameter with the SOC of the battery over the region of interest; transforming with the processor a combination of the generated one or more curves into one or more supplemental curves to express the a priori relationship based on cell chemistry between a second parameter and one or more of current (I), polarization current (Ip), and open circuit voltage (OCV), and a voltage slope with respect to SOC(dOCV/dSOC); measuring a voltage and a current of the battery during a period of time to create a set of voltage and current data; processing with the processor the set of voltage and current data to create a set of processed data; combining with the processor the one or more generated curves with the processed data to generate processed data as a function of SOC; regressing with the processor the process data at multiple SOCs over the region of interest with respect to an equation which is representative of the battery to generate a curve that evaluates each SOC for accuracy; selecting the SOC that minimizes errors; and outputting the selected SOC for display to a user on a user-interface; wherein Rp1(SOC,Ip)*Rp2(T) and Rohmic is used to track pulse (discharge) and regen (charge) peak power or track pulse (discharge) and regen (charge) power at any current or voltage discharge, where Rp1(SOC,Ip) is polarization resistance relative to SOC, Rp2(T) is polarization resistance relative to temperature, and Rohrnic is ohmic resistance.