Method and device for measuring secondary cell internal impedance and judging deterioration

摘要

A method for measuring the internal impedance of a secondary battery, the method comprises the steps of:
measuring the input currents and the responsive voltages to the input currents at charge or discharge;
acquiring plural of current measurement values and voltage measurement values on time axis;
calculating amplitude of the input currents and amplitude of the responsive voltages at a predetermined frequency from the acquired plural current measurement values and the acquired plural voltage measurement values by means of Fourier transformation; and calculating internal impedances at the predetermined frequency as the result of dividing the amplitude of the responsive voltages at the predetermined frequency by the amplitude of the input currents at the predetermined frequency.
A device for performing the method.
Further methods and devices for measuring the internal impedance of a secondary battery and for determining the deterioration of a secondary battery.