A battery pack in one aspect of the present disclosure includes a first cell, a memory device, a target current calculator, and an information notifier. The memory device stores a maximum variation of a charging current value. The maximum variation is determined depending on a characteristic of the battery pack. The target current calculator calculates a newest value of a target current value based on (i) a previous value of the target current value and (ii) the maximum variation. The information notifier transmits a charge condition information including the newest value.