Battery pack

A battery pack includes a non-aqueous electrolyte secondary battery, a rigid covering member, and a protection circuit board. The secondary battery includes a battery element and a flexible covering member formed of a first laminated film composed of a first heat-bonding layer, a first metal layer, and a first outer covering layer laminated successively. The flexible covering member is sealed along around the battery element while leaving electrode terminals of the positive and negative electrodes extended outside the battery element. The rigid covering member is formed of a second laminated film composed of a second heat-bonding layer, a second metal layer, and a second outer covering layer laminated successively. The flexible covering member and the rigid covering member are bonded with an adhesive strength equal to or higher than atmospheric pressure and with a peel strength equal to or lower than a breaking strength of the flexible covering member.