A battery pack including a battery cell, a plurality of electrode tabs coupled to and extending from terminals of the battery cell, a protect circuit module (PCM) to control charging and discharging of the battery cell, a flexible printed circuit board (FPCB) including a plurality of connection pads coupled to the electrode tabs and electrically coupling the battery cell to the PCM, and a case accommodating the battery cell, the electrode tabs, the PCM, and the FPCB, wherein the case includes a first case accommodating the battery cell and a second case covering the first case, and wherein the first case includes ribs extending toward the second case and has cut-out grooves at regions corresponding to the connection pads.