DETERIORATION MEASUREMENT DEVICE, SECONDARY BATTERY PACK, DETERIORATION MEASUREMENT METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a technique for improving accuracy in measuring the deterioration of a secondary battery.

SOLUTION: A battery detection part measures voltage between both ends of a secondary battery. A current detection part measures current flowing through the secondary battery. A control part holds in advance a value of an external impedance located outside the secondary battery in a discharge path; discharges the secondary battery from a first measurement time to a second measurement time at which a discharge capacity integrated on the basis of a discharge current measured by the current detection part reaches a predetermined discharge capacity reference value; calculates, at the second measurement time, an internal impedance located inside the secondary battery on the basis of the voltage measured by the battery detection part; multiplies the sum of the external impedance and the internal impedance by the discharge current measured by the current detection part so as to calculate a second open circuit voltage at the second measurement time; and calculates the return capacity of the secondary battery on the basis of a first open circuit voltage, the second open circuit voltage, and the discharge capacity reference value at the first measurement time.

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