A
polymer battery pack includes: a bare
cell having main walls and sub-walls; a protection circuit member which is electrically connected to the bare
cell; a resin sheath which encloses the sub-walls of the bare
cell in such a way that the main walls are exposed to the outside; and finishing tape attached to the main walls of the bare cell. A frame case may be interposed between the bare cell and the resin sheath. In the
battery pack, a strong resin sheath and finishing tape or a frame case are engaged with the bare cell, thereby reinforcing the strength of the bare cell and improving the reliability of the bare cell. Also, the
battery pack does not require a separate space for the supersonic
welding, and thus can receive a bare cell of
high capacitance. A method of manufacturing the
polymer battery pack includes forming a bare cell, forming a core pack by positioning and electrically interconnecting a protection circuit member with the bare cell, and molding a resin sheath accommodating the resin sheath enclosing the core pack and the
electrode terminals of the protection circuit member are exposed to the outside. A frame case can be formed and engaged with the bare cell to be included in the core pack.