Battery management apparatus, battery management method, and battery energy storage system

A battery management apparatus, for improving accuracy in calculating a mid voltage of a battery that is chargeable and dischargeable and efficiently controlling the battery, comprising:

• a battery state calculator that calculates a state of charge, a capacity deterioration degree, and a resistance deterioration degree of the battery;
• a mid voltage calculator that corrects the calculated resistance deterioration degree, corrects a mid resistance of the battery corresponding to the mid voltage according to a correction coefficient in accordance with the corrected resistance deterioration degree, and calculates the mid voltage that is present between a charge-discharge voltage in a current state of charge of the battery, and a charge-discharge voltage in a minimum state of charge or a maximum state of charge of the battery, based on the corrected mid resistance;
• a remaining capacity calculator that calculates a remaining capacity or a chargeable capacity of the battery, based on the state of charge and the capacity deterioration degree;
• and
• an available energy calculator that calculates available energy or chargeable energy of the battery, based on the mid voltage and the remaining capacity, or on the mid voltage and the chargeable capacity, and
• wherein the battery management apparatus controls a charge or a discharge of the battery based on the available energy or the chargeable energy.