Abstract: An electrochemical battery system in one embodiment includes at least one electrochemical cell, a current sensor configured to generate a current signal, a voltage sensor configured to generate a voltage signal, a memory in which command instructions are stored, and a processor configured to execute the command instructions to obtain the current signal and the voltage signal, and to generate an estimated cell nominal capacity (Cnom) of the at least one electrochemical cell by estimating a first leg Cnom during a first charging sequence using a first charging current, estimating a second leg Cnom during a second charging sequence using a second charging current, wherein the second charging current is at a current amplitude different from the current amplitude of the first charging current, and generating the cell Cnom based upon the first leg Cnom and the second leg Cnom.

Abstract: A method of monitoring a battery with a controller identifies appropriate times for estimating a state of the battery. The method includes identifying a persistence of excitation in the battery, identifying a magnitude of an electrical current that is supplied to the battery, and performing a state estimation process for the battery only in response to the identified persistence of excitation exceeding a first predetermined threshold and the identified magnitude of the electrical current exceeding a second predetermined threshold.

Abstract: An electrochemical battery system in one embodiment includes at least one electrochemical cell, a first sensor configured to generate a current signal indicative of an amplitude of a current passing into or out of the at least one electrochemical cell, a second sensor configured to generate a voltage signal indicative of a voltage across the at least one electrochemical cell, a memory in which command instructions are stored, and a processor configured to execute the command instructions to obtain the current signal and the voltage signal, and to generate an estimated SOC and kinetic parameters for an equivalent circuit model of the at least one electrochemical cell by obtaining a derivative of an open cell voltage, obtaining an estimated nominal capacity of the at least one electrochemical cell, estimating the kinetic parameters using a modified least-square algorithm with forgetting factor, and estimating the SOC using the estimated kinetic parameters.

Abstract: An electrochemical battery system in one embodiment includes at least one electrochemical cell, a current sensor configured to generate a current signal, a voltage sensor configured to generate a voltage signal, a memory in which command instructions are stored, and a processor configured to execute the command instructions to obtain the current signal and the voltage signal, and to generate an estimated cell nominal capacity (Cnom) of the at least one electrochemical cell by estimating a first leg Cnom during a first charging sequence using a first charging current, estimating a second leg Cnom during a second charging sequence using a second charging current, wherein the second charging current is at a current amplitude different from the current amplitude of the first charging current, and generating the cell Cnom based upon the first leg Cnom and the second leg Cnom.

Abstract: An electrochemical battery system in one embodiment includes at least one electrochemical cell, a first sensor configured to generate a current signal indicative of an amplitude of a current passing into or out of the at least one electrochemical cell, a second sensor configured to generate a voltage signal indicative of a voltage across the at least one electrochemical cell, a memory in which command instructions are stored, and a processor configured to execute the command instructions to obtain the current signal and the voltage signal, and to generate kinetic parameters for an equivalent circuit model of the at least one electrochemical cell by obtaining a derivative of an open cell voltage (Uocv), obtaining an estimated nominal capacity (Cnom) of the at least one electrochemical cell, and estimating the kinetic parameters using a modified least-square algorithm with forgetting factor.