Patent ID: 6453249
Filing Date: 2002-09-17
Classification: G01R,H02J

Abstract:
An apparatus for judging deterioration of a battery, comprising:current detector for detecting output electric current from and regenerative electric current to said battery; voltage detector for detecting a voltage output from said battery; integrator for calculating a remaining charge in said battery by integrating the result of detection by said current detector; threshold voltage calculator for calculating a first judgment voltage corresponding to a battery voltage when the remaining charge in said battery indicates a first value, and a second judgment voltage corresponding to a battery voltage when the remaining charge in said battery indicates a second value, based on the electric current value filtered by said filter; comparator for comparing the first and second judgment voltage, calculated by said threshold voltage calculator, with the output voltage value from said battery; corrector for correcting the remaining charge to said first or second value when the output voltage value has reached said first and second judgment voltage; current integrator for integrating the output current from the battery and the regenerative current after the remaining charge was corrected to said first value until the remaining charge is corrected to said second value; and a deterioration judgment device for judging the deterioration of said battery when the value obtained from the integration by said current integrator is equal to or below a predetermined deterioration criterion.