A rechargeable battery pack comprising: a plurality of sets of unit cells, wherein each unit cell includes a rechargeable battery and, in each set, the respective unit cells are electrically connected and arranged consecutively in a first direction; a plurality of rechargeable battery modules, wherein each of the rechargeable battery modules comprises a corresponding set of the unit cells and a pair of end plates respectively located on outermost opposing sides thereof; and a coupling member connecting the end plates of the rechargeable battery modules to each other, wherein each of the end plates includes: a main body oriented toward an outermost unit cell among the unit cells of the respective rechargeable battery module; a bent portion having at least one bend away from a side of the main body; a first flange having a first width and a second flange having a second width smaller than the first width, wherein the second flange extends from the bent portion and the first flange extends from a middle portion of the second flange and is connected to the coupling member; a first bent line defining a first bend between the bent portion and the second flange; a second bent line defining a second bend between the main body and the bent portion; and a third bent line defining a third bend situated between the first and second bent lines, wherein the third bend is bent in an opposite direction to the first and second bends, wherein the first and second bends are bent in a direction away from the corresponding unit cell, and wherein the third bend is bent towards the corresponding unit cell. a plurality of sets of unit cells, wherein each unit cell includes a rechargeable battery and, in each set, the respective unit cells are electrically connected and arranged consecutively in a first direction; a plurality of rechargeable battery modules, wherein each of the rechargeable battery modules comprises a corresponding set of the unit cells and a pair of end plates respectively located on outermost opposing sides thereof; and a coupling member connecting the end plates of the rechargeable battery modules to each other, wherein each of the end plates includes: a main body oriented toward an outermost unit cell among the unit cells of the respective rechargeable battery module; a bent portion having at least one bend away from a side of the main body; a first flange having a first width and a second flange having a second width smaller than the first width, wherein the second flange extends from the bent portion and the first flange extends from a middle portion of the second flange and is connected to the coupling member; a first bent line defining a first bend between the bent portion and the second flange; a second bent line defining a second bend between the main body and the bent portion; and a third bent line defining a third bend situated between the first and second bent lines, wherein the third bend is bent in an opposite direction to the first and second bends, wherein the first and second bends are bent in a direction away from the corresponding unit cell, and wherein the third bend is bent towards the corresponding unit cell. a main body oriented toward an outermost unit cell among the unit cells of the respective rechargeable battery module; a bent portion having at least one bend away from a side of the main body; a first flange having a first width and a second flange having a second width smaller than the first width, wherein the second flange extends from the bent portion and the first flange extends from a middle portion of the second flange and is connected to the coupling member; a first bent line defining a first bend between the bent portion and the second flange; a third bent line defining a third bend situated between the first and second bent lines, wherein the third bend is bent in an opposite direction to the first and second bends, wherein the first and second bends are bent in a direction away from the corresponding unit cell, and wherein the third bend is bent towards the corresponding unit cell.