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.
1. A charging system for a secondary battery comprising:
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,
wherein 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,
the charging system further comprising:
a unit that calculates a degree of degradation of the secondary battery based on the DC resistance of the secondary battery,
wherein the charge termination capacity is changed based on a calculation result of the degree of degradation.
2. The charging system for a secondary battery according to claim 1 , wherein the charge termination capacity is determined based on a full charge capacity that is based on a second voltage less than the first voltage.
3. The charging system for a secondary battery according to claim 2 , wherein the second voltage is set in a range greater than or equal to 95% and less than or equal to 99% of the first voltage.