Abstract: A battery pack including a battery coupled to a load and a charging device, and comprising at least one battery cell, and a battery management unit for controlling charging of the battery from the charging device and discharging of the battery to the load, wherein the battery management unit includes a measuring unit for generating cell voltage data and current data by measuring a cell voltage and a current of the at least one battery cell, a capacity estimating unit for generating current capacity data based on the cell voltage data and the current data, an internal resistance estimating unit for generating current internal resistance data based on the cell voltage data and the current data, and a state of health (SOH) estimating unit for estimating an SOH of the at least one battery cell based on the current capacity data and the current internal resistance data.