SECONDARY BATTERY CHARGING SYSTEM

A charging system for a secondary battery capable of minimizing a reduction in the capacity retention rate and the charge-discharge efficiency of a secondary battery. A charging system according to an aspect of the present disclosure includes a secondary battery, a charger that charges the secondary battery, a unit that calculates a charge capacity of the secondary battery, and a charge control unit that controls the charger to perform a first charging step of charging the secondary battery until a first voltage is reached, and a second charging step of charging the secondary battery at a constant voltage of the first voltage. The charge control unit terminates charging when the charge capacity of the secondary battery reaches a charge termination capacity set in a range less than a full charge capacity that is based on the first voltage of the secondary battery.