Patent ID: 9531040
Filing Date: 2016-12-27
CPC Classification: G01R,H01M,Y02E

Claim Text:
1. A battery system comprising: a secondary battery, a degree of degradation of which is measured; a memory portion configured to store specific information including: a measurement frequency, a measurement temperature, and an initial limiting capacitance of one secondary battery having a same specification as a specification of the secondary battery; a temperature measuring section configured to measure a temperature of the secondary battery; a power supply section configured to apply an alternating current signal having the measurement frequency of 1 mHz or more but less than 3 mHz, to the secondary battery at the measurement temperature of 40° C. or higher but 70° C. or lower, based on the specific information in the memory portion; a measuring portion configured to measure an impedance of the secondary battery by the alternating current signal that the power supply section applies; a calculating portion configured to calculate the degree of degradation by using a limiting capacitance of the secondary battery, which is calculated using a measurement value of the measuring portion, and the initial limiting capacitance; and a heating section configured to heat the secondary battery to the measurement temperature, wherein the memory portion is configured to store the measurement frequency in plurality, wherein the power supply section is configured to apply the plurality of measurement frequencies to the secondary battery, wherein the calculating portion is configured to calculate the limiting capacitance by using a plurality of measurement values at the plurality of measurement frequencies, and wherein the calculating portion is configured to calculate the limiting capacitance by using a measurement value which is 95% or more of a measurement value at a lowest frequency out of the plurality of measurement frequencies.