| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for discriminating secondary cell degradation capable of discriminating degradation conditions of secondary cells in high accuracy, by precisely correcting temperature characteristics of the internal impedance, according to degradation conditions of secondary cells. SOLUTION: In the secondary cell degradation discrimination technique, a plurality of formulae of temperature characteristics, approximating the temperature properties of internal impedance of a secondary cell are set, preliminarily depending on the different degradation conditions of secondary cell; a measured internal impedance value and measured temperature are acquired (steps S102 to S104), by measuring the internal impedance and the temperature of the secondary cell at a predetermined timing; internal impedance values of a plurality of formulae of temperature properties at the measured temperature are compared with the measured value of internal impedance, based on the compared result; temperature correction computation is implemented using the internal impedance value of a plurality of aforementioned formulae of temperature properties at a predetermined reference temperature, to derive the reference internal impedance at the reference temperature (step S106); and finally, the degradation condition of the secondary cell is discriminated, on the basis of the derived reference internal impedance (steps S107 to S109). COPYRIGHT: (C)2007,JPO&INPIT
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