A battery including an electrode assembly including a positive electrode, a negative electrode, and a separator therebetween; a case housing the electrode assembly; a cap plate coupled to the case; a collector plate coupled to the electrode assembly; and a terminal coupled to the collector plate and passing through the cap plate, wherein the terminal includes a terminal protrusion and a bottom protrusion, the collector plate includes an electrode region coupled to the electrode assembly and a terminal region coupled to the terminal, the terminal region including a combining hole passing therethrough, the combining hole having a noncircular shape, and the bottom protrusion of the terminal has an interengaging, matching shape relative to the combining hole, passes through the combining hole of the collector plate, and is welded to a lower surface of the collector plate.