US Patent 9244132 Systems and methods for determining battery state-of-health

A system and method use an open-circuit voltage (OCV) method of calculating a state-of-health (SOH) of a chemical battery. The OCV system and method includes charging the battery to a maximum charge potential, determining an open-circuit voltage (OCV) of the battery after waiting a predetermined period of time after completion of the charging, and determining the SOH of the battery based on the determined OCV of the battery. Another system and method use a time-to-charge (TTC) method of calculating a state-of-health (SOH) of a chemical battery. The TTC system and method includes monitoring and storing a charge time of the battery in a memory and scaling the stored charge time to form an SOH indication.