SECONDARY BATTERY STATE-OF-CHARGE MEASURING APPARATUS, SECONDARY BATTERY STATE-OF-CHARGE MEASURING METHOD, AND SECONDARY BATTERY CHARGER

摘要

PROBLEM TO BE SOLVED: To provide a secondary battery state-of-charge measuring apparatus, a secondary battery state-of-charge measuring method, and a secondary battery charger capable of accurately and quickly measuring a state of charge of a secondary battery.SOLUTION: In a state-of-charge measuring apparatus 1 for a secondary battery 100 including: a power supply unit 2 supplying a charge voltage to the secondary battery 100; charge control means 5 controlling charging on the secondary battery 100; charge-current detection means 6 for the secondary battery 100; and voltage detection means 7 detecting a voltage between terminals of the secondary battery 100, the charge control means 5 causes PWM means 43 changing a charge current carried to the secondary battery 100 to fluctuate the charge current, and causes the voltage detection means 7 to acquire a plurality of voltages between the terminals of the secondary battery 100 depending on fluctuation values of the charge current detected by the charge-current detection means 6, and performs a regression analysis using the fluctuation values of the charge current and the voltage between the terminals of the secondary battery 100, thereby calculating a battery electromotive force Vemf and a dynamic internal resistance Dir of the secondary battery 100.