REVERSIBLE CAPACITY ESTIMATION METHOD OF NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, LIFE PREDICTION METHOD, REVERSIBLE CAPACITY ESTIMATION METHOD, LIFE PREDICTION DEVICE AND POWER STORAGE SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a reversible capacity estimation method of a nonaqueous electrolyte secondary battery capable of precisely and easily measuring a deteriorated state of the nonaqueous electrolyte secondary battery such as a lithium ion secondary battery in the long term.SOLUTION: In the reversible capacity estimation method, the reversible capacity which is a capacity capable of charging and discharging a secondary battery 200 is estimated by a computer. This method includes: an acquisition step of acquiring an AC impedance at a predetermined frequency in the secondary battery 200 (S204); and an estimation step (S206) of estimating the reversible capacity by using the acquired AC impedance and a linear relational expression showing the relationship between the AC impedance and the reversible capacity (S206).