Apparatus and method for detecting internal impedance of a battery and a degree of battery degradation based on detected internal impedance

摘要

An internal impedance detecting apparatus for detecting the internal impedance of a secondary battery with high accuracy is provided. Processor 106 divides the variation of each voltage detected by voltage change detector 103 by the variation of the current detected by current change detector 105 for the same detecting time as that for the voltage variations to compute the internal impedances. Judging unit 107 checks the variations of the internal impedances computed by processor 106 and judges from the check result whether or not the internal impedances have reliability. Only when judging unit 107 judges that the internal impedances have reliability, generator 109 generates output internal impedance according to the internal impedances.