Secondary battery internal resistance calculation device and internal resistance calculation method thereof, secondary battery abnormality detection device and abnormality detection method thereof, secondary battery degradation estimation device and degradation estimation method thereof

摘要

PROBLEM TO BE SOLVED: To provide an internal resistance calculation apparatus for secondary batteries capable of improving calculation accuracy of an internal resistance value.SOLUTION: An internal resistance calculation apparatus 10 for secondary batteries includes: a voltage measuring unit 3 that is connected between a positive electrode terminal and a negative electrode terminal of each battery cell 1 constituting a secondary battery and measures an interterminal voltage; a current measuring unit 4 that is inserted into a current route and measures charge/discharge currents with respect to the battery cell 1; a control unit 6 that controls measurements in the voltage measuring unit 3 and the current measuring unit 4; and an arithmetic unit 8 that is connected to the control unit 6, performs wavelet transformation from each measurement value of the voltage measuring unit 3 and the current measuring unit 4, obtains wavelet coefficients of the current and the voltage for every frequency and calculates the internal resistance of the secondary battery from a ratio thereof.