INTERNAL RESISTANCE MEASUREMENT DEVICE AND METHOD FOR STACKED BATTERY

An internal resistance measurement device (5) for stacked battery includes an AC power supply part for outputting an AC current to an measurement-object, which includes at least a stacked battery made of a plurality of stacked power generating elements, by being connected to the measurement-object, an AC adjusting part (540) for adjusting an AC current so that a positive-electrode AC potential difference, which is a potential difference obtained by subtracting potential in a middle portion from potential in a portion connected to a load device on the positive side of the measurement-object, matches a negative-electrode AC potential difference, which is a potential difference obtained by subtracting potential in the middle portion from potential in a portion connected to the load device on the negative side of the measurement-object, and a resistance calculating part (550) for calculating resistance of the battery based on the adjusted AC current and the AC potential difference.