A battery pack may include a battery cell; a control board disposed above the battery cell and connected to the battery cell; a plurality of terminals disposed on the control board and disposed side by side in a left-right direction; a plurality of partition wall disposed on the control board; and an outer case housing the battery cell, the control board, the plurality of terminals, and the plurality of partition walls, and having an upper surface comprising a terminal reception part configured to receive a terminal of the power tool. The plurality of terminals may include a first terminal and a second terminal adjacent to the first terminal in the left-right direction. At least two of the partition walls are disposed between the first terminal and the second terminal.