Patent ID: 7534525

Claim:
A method for producing a battery pack comprising: a first step of housing a battery element having a cathode, an anode, a polymer electrolyte, and terminals being drawn from the cathode and the anode, in a recessed part of a package body, said package body having (a) first area having a recessed part (b) a second area contiguous to the first area and forming a substantially straight line between the first area and the second area (c) a third area contiguous to the second area and forming a substantially straight second line between the second area and the third area such that the second line is substantially perpendicular to the first line; a second step of covering the battery element with the second area by folding the second area at a first folding edge located where the first area and the second area meet such that the second area is folded over a first surface of the first area so as to cover any exposed surface of the battery element with the second area, the third area now adjacent to the first area as a result of folding the second area over the first surface of the first area, and joining the first area to the second area; a third step of connecting the terminals of the battery element to a connecting board having a terminal part electrically connected to an external device, providing a frame in the periphery of the housing recessed part in which the battery element is housed and disposing the connecting board in the frame; a fourth step of covering the second surface of the first area by folding the third area of the package body at a second folding edge located where the second area and the third area meet such that the third area is folded over a second surface of the first area; and a fifth step of joining the third area to the first area wherein, the packaged body is folded along the first folding edge so that the second area is in contact with the first area along a periphery of the battery element, and the packaged body is folded along the second folding edge so that third area overlies and is in contact with an exposed surface of the first area.