Patent ID: 8060323

Claim:
A secondary-battery life estimation apparatus, comprising: a voltage measuring portion configured to measure a terminal voltage V of a secondary battery; a first memory configured to store in advance a terminal voltage V 0 of a non-degraded secondary battery before the non-degraded secondary battery discharges after a preset time for stabilizing a terminal voltage V of the non-degraded secondary battery elapses since the non-degraded secondary battery is fully charged and charge thereof is terminated; a second memory configured to store in advance a life-estimation data map as a look-up table associating a voltage difference dV between a terminal voltage V of the secondary battery before the secondary battery discharges after the preset time elapses since the secondary battery is fully charged and charge thereof is terminated, and the terminal voltage V 0 with a residual life of the secondary battery; and a CPU configured to calculate the voltage difference dV between the terminal voltage V measured by the voltage measuring portion before the secondary battery discharges after the preset time elapses since the secondary battery is fully charged and charge thereof is terminated, and the terminal voltage V 0 stored in the first memory and estimate the residual life of the secondary battery based on the life-estimation data map stored in the second memory using the calculated voltage difference dV.