Lid for battery case

A lid for a battery case that is formed from metal plate that constitutes the battery case (3), comprising:

• a lid main body (4) that is formed in a rectangular shape having a short side (40) and a long side (41) when seen from above;
• a safety valve (5) that includes an annular thin portion (50) formed integrally with the lid main body (4) by coining, and which ruptures when an internal pressure of the battery case (3) exceeds a predetermined value, thereby releasing the internal pressure of the battery case (3) to the outside;
• and
• a bulging portion (6) formed integrally with the lid main body (4) so as to bulge out from the lid main body (4),
• wherein the bulging portion (6) includes a vertical wall (60) that extends from the lid main body (4), and a flat portion (61) provided on an end portion of the vertical wall (60) such that a periphery thereof is surrounded by the vertical wall (60), and
• the safety valve (5) is provided in the flat portion (61) of the bulging portion (6).