Patent ID: 8994322
Filing Date: 2015-03-31
Classification: H01M,H02J,Y02E

Abstract:
1. A secondary battery system comprising: a battery module having at least one lithium ion battery; a measuring device for measuring a voltage and a temperature of the battery module; a state of charge detection device for detecting a state of charge based on the voltage; and a charge-discharge control device; wherein an estimated battery resistance of the battery module, corresponding to the state of charge and the temperature of the battery module, is calculated by the charge-discharge control device based on a standard battery resistance, a standard initial battery resistance, and a measured initial battery resistance; the standard battery resistance is calculated based on a standard operating condition of the battery module; the standard initial battery resistance is calculated based on a standard initial condition of the battery module; the measured initial battery resistance is calculated based on a measured initial condition of the battery module; and the charge-discharge control device calculates the estimated battery resistance using a formula R=[(R′×R0)/R0′]; wherein R is the estimated battery resistance, R′ is the standard battery resistance, R0′ is the standard initial battery resistance, and R0 is the measured initial battery resistance.