IMPEDANCE MEASURING DEVICE AND CONTROL METHOD FOR IMPEDANCE MEASURING DEVICE

An impedance measuring device outputs an alternating current of a prescribed frequency to each of a positive electrode terminal and a negative electrode terminal of a laminated type battery and detects an alternating-current potential difference between the positive electrode terminal and an intermediate-point terminal and an alternating-current potential difference between the negative electrode terminal and the intermediate-point terminal. The impedance measuring device adjusts an amplitude of the alternating current such that the alternating-current potential difference between the positive electrode terminal and the intermediate-point terminal and the alternating-current potential difference between the negative electrode terminal and the intermediate-point terminal coincide, and computes an impedance on the basis of the adjusted alternating current and alternating-current potential differences. Then, the impedance measuring device corrects a phase difference of the alternating currents output to the positive electrode terminal and the negative electrode terminal on the basis of a phase difference between an alternating-current potential generated at the positive electrode terminal and an alternating-current potential generated at the negative electrode terminal.