| 摘要 |
PROBLEM TO BE SOLVED: To estimate a capacity deterioration in a secondary battery with high accuracy.SOLUTION: A target secondary battery is charged, an open circuit voltage of the secondary battery (5) just after charging completion is measured to determine a reference open circuit voltage, the secondary battery (5) is stored isothermally, an open circuit voltage of the secondary battery (5) in isothermal preservation is measured, a drop voltage is determined as difference between the reference open circuit voltage and the open circuit voltage in the isothermal preservation, a self-discharge coefficient is determined as a functional coefficient to a lapse time of the drop temperature in the isothermal preservation, and a capacity reduction rate of the second battery (5) is determined from the determined self-discharge coefficient by using a relation between the self-discharge coefficient prepared in advance and the capacity reduction rate. |
