Battery pack for the motorized device

A battery pack (1) for a motor-operated device includes a battery (10) having a plurality of cells (11, 12, 13, 14, 15), a Zellenentladeeinheit (21, 22, 23, 24, 25), each cell individually discharges a voltage detection unit (30, 41) that detects each cell voltage, a target cell determination unit (41) and a Entladesteuerungseinheit (41). If at least one cell is present, which has the cell voltage is equal to or smaller than a predetermined threshold value, the cell voltage, which is the klei Neste among them is set as a minimum cell voltage, and if at least one other cell is present, the by a specified value or more larger cell voltage than the smallest cell voltage, or having at the predetermined value or more larger cell voltage than the threshold value, the target cell determination unit (41) determines the at least one cell as a target cell and causes the Entladesteuerungseinheit (41) that the target cell by the Zellenentladeeinheit (21, 22, 23, 24, 25) is discharged.