A master controller of a battery charge and discharge control apparatus is a device performing charge and discharge control on a group of a predetermined number of battery arrays, the battery arrays being connected together in parallel. The master controller acquires an entire charge or discharge instruction intended for the entire battery array group, starts charging or discharging each of the battery arrays at a uniform charge or discharge power value, acquires a charge or discharge status of each of the battery arrays after the beginning of the charge or discharge and compares the charge or discharge status with a predetermined charge or discharge set value for the entire battery array group, and changes the charge or discharge power value of each of the battery arrays based on a result of the comparison.