Patent ID: 8741459
Filing Date: 2014-06-03
Classification: B60K,B60L,B60W,G01R,H01M,H02J,Y02E,Y02T

Abstract:
1. A state judging device of a secondary battery, the device comprising: a unit which measures a voltage of a secondary battery; a unit which measures a current of the secondary battery; a unit which supplies a calculated internal resistance of the secondary battery based on the measured voltage and the measured current; a unit which supplies a calculated SOC of the secondary battery; a unit programmed to store an initial relationship characteristic and SOC defined as a function of internal resistance with respect to SOC regions when an SOC region to be used is divided into a low SOC region, an intermediate SOC region, and a high SOC region of an initial state of the secondary battery, the initial state corresponding to a state wherein a capacity balance between a cathode and an anode is set wherein one of capacities of the anode and the cathode is greater than a capacity of the other one by a predetermined value; a unit programmed to store a calculated relationship characteristic defined as a function of the calculated internal resistance with respect to the calculated SOC after a period has elapsed for the secondary battery; and a unit programmed to judge a change of the capacity balance between the cathode and the anode of the secondary battery from the initial state when the calculated relationship characteristic changes from the initial relationship characteristic.