An system is provided that includes a first circuit that serially connects storage battery units, second circuits, and adjusters that adjust an amount of current flowing at the second circuits. The system also includes a controller that executes at least one of first control, where voltage at a first storage battery unit is made to be higher than voltage at a second storage battery unit regarding which prediction has been made that a degree of deterioration will be greater than the degree of deterioration of the first storage battery unit, and charging is stopped. The system further includes second control, where the adjusters are controlled and voltage at the first storage battery unit is made to be lower than voltage at the second storage battery unit, and discharging is stopped.