A battery pack that allows a cover to be firmly fixed with a simple structure and that has superior impact resistance is provided. The battery pack is a battery pack 1 in which a protection circuit 10 and a protection element 7 are attached to a unit cell 2 and the protection circuit 10 and the protection element 7 are housed within a cover 11 , the battery pack 1 including an internal frame 6 provided within the cover 11 , wherein the internal frame 6 is fixed to the unit cell 2 and supports the protection circuit 10 , a boss 13 projecting from the internal frame 6 which passes through a hole 12 formed in the cover 11 , and the cover 11 is fixed to the internal frame 6 by melting and deforming the boss 13.
1. A battery pack in which a protection circuit and a protection element are attached to a unit cell and the protection circuit and the protection element are housed within a cover, the battery pack comprising:
an internal frame provided within the cover,
wherein the internal frame is fixed to the unit cell and supports the protection circuit,
a boss projecting from the internal frame which passes through a hole formed in the cover,
wherein the hole formed in the cover is in a position depressed below a surface of the cover, and a face that extends directly from a boundary of the hole is inclined with respect to a face containing the boundary of the hole so as to get closer to the surface of the cover as a distance from the boundary of the hole increases, and
wherein the cover is fixed to the internal frame by melting and deforming the boss.