TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Battery: In the secondary battery, the protection circuit assembly includes a protection circuit plate having a first plate and a second plate, the first plate is metal and covers an opening of the can, and the second plate includes an insulating layer and a conductive metal pattern, and is on the first plate. The lower surface of the second plate faces and is in contact with an upper surface of the first plate. The distance between opposing short sides of the second plate is shorter than a distance between opposing short sides of the first plate. The distance between opposing long sides of the second plate is shorter than a distance between opposing long sides of the first plate. The outermost portion of the first plate is welded to an upper end portion of the can. The first plate is aluminum. The second plate is made of an epoxy resin. The second plate is a flexible printed circuit board. The protection circuit assembly includes a terminal part on a lower surface of the second plate to electrically connect the first plate to the conductive metal pattern. The protection circuit assembly includes a protection circuit device at one side of the second plate, and the terminal part is electrically connected to an electrode terminal. The protection circuit assembly includes a charge/discharge terminal part on the second plate, the charge/discharge terminal part being electrically connected to the conductive metal pattern to electrically connect the bare cell to an external device. The charge/discharge terminal part includes a housing and charge/discharge terminals mounted on a surface of the second plate. The housing is made of an insulating material, and the charge/ discharge terminals include metal plates. The metal plates serve as a positive electrode, a resistor, and a negative electrode. The protection circuit assembly comprises a protection circuit device positioned between the second plate and the charge/discharge terminal part. The protection circuit assembly has a terminal hole at the center, and the cap assembly includes an electrode terminal inserted into the terminal hole. The protection circuit assembly includes a lead plate on the second plate, the lead plate being electrically connected to the electrode terminal and the conductive metal pattern. The protection circuit assembly includes protection circuit devices on the second plate and electrically connected to the conductive metal pattern.