Prismatic secondary battery

The present invention addresses the problem of obtaining a prismatic secondary battery that has a battery external surface that is insulated and watertight such that no short circuit occurs between battery containers of adjacent batteries, or between a battery container and the case of a battery pack, due to condensation water, or the like. To solve the above problem, the present invention provides a prismatic secondary battery (90) having a battery container in which the six sides thereof are covered by a sheet of insulation film (50), said prismatic secondary battery (90) being characterized in that the end portions of the insulation film are joined overlapping one another, and the insulation film continuously covers the sides of the battery container that are adjacent to each other across the ridges of the battery container. 本发明的课题是得到种方形二次电池，该电池的外表面具有绝缘性和水密性，相邻电池的电池罐彼此之间、或者电池罐与电池组的框体之间不存在因冷凝水等引起的短路。为了解决上述课题，本发明的方形二次电池(90)，是通过张绝缘膜(50)覆盖电池容器的六个面的方形二次电池，所述绝缘膜的端部彼此相互叠合，该绝缘膜连续地覆盖将所述电池容器的各棱线夹持在其间的相互邻接的面。