A rechargeable battery pack is disclosed. In one aspect, the rechargeable battery pack includes multiple a plurality of sets of unit cells adjacently placed to each other, wherein each unit cell includes a rechargeable battery and a plurality of rechargeable battery modules each configured to electrically connect a corresponding set of the unit cells to each other, wherein each rechargeable battery module includes a pair of end plates respectively placed on outermost opposing sides thereof. The rechargeable battery pack also includes a coupling member connecting the end plates of the rechargeable battery modules to each other. Each of the end plates includes a first flange having a first width and extending from a bent portion of a main body to be fastened to the coupling member and a second flange having a second width smaller than the first width and extending from a middle portion of the first flange.