Patent ID: 8204702

Claim:
A method for estimating a remaining operating life of an electrical energy storage device electrically operatively connected to an electric machine of a hybrid powertrain system, comprising: monitoring temperature, state-of-charge, and electric current during both charging and discharge events of the electrical energy storage device during a predetermined time interval; determining an electric current discharge comprising integrating the electric current during the discharge events of the electrical energy storage device during the predetermined time interval; determining a temperature factor and a state-of-charge factor based upon the monitored temperature and the monitored state-of-charge during the predetermined time interval; calculating a battery life metric during the predetermined time interval based upon the temperature factor, the state-of-charge factor, and the electric current discharge, wherein the battery life metric accounts for the electric current discharge during the predetermined time interval and does not account for the electric current during the charging of the electrical energy storage device during the predetermined time interval; determining a total battery life metric based on the calculated battery life metric; and determining the remaining operating life of the electrical energy storage device based upon the total battery life metric.