RECTANGULAR-PRISM-SHAPED SECONDARY BATTERY

摘要

The purpose of this invention is to yield a rectangular-prism-shaped secondary battery, the positive-electrode/negative-electrode orientation of which can be ascertained from the bottom of the case thereof. This invention is a rectangular-prism-shaped secondary battery (C1) that has the following: a battery case (1) that has a rectangular bottom surface (22); a battery lid (6) that seals an opening (100) opposite the bottom surface (22) of the battery case (1); a positive-electrode external terminal (8A) and a negative-electrode external terminal (8B) provided on the battery lid (6); and a gas-discharge valve (10) provided in the battery lid (6). Said rectangular-prism-shaped secondary battery (C1) is characterized in that the outside of the bottom surface (22) of the battery case (1) is provided with marks (50) that are shaped asymmetrically about a first centerline (LC1) that is perpendicular to the long sides of the bottom surface (22) and/or a second centerline (LC2) that is perpendicular to the short sides of the bottom surface (22).