Patent attributes
A battery pack includes a plurality of batteries interlocked linearly through a connector. The connector includes an inner peripheral portion to be welded to one battery, and an outer peripheral portion, provided outside the inner peripheral portion, to be welded to the other battery. The inner peripheral portion and the outer peripheral portion have a step in between, and the step places the inner peripheral portion in a concave portion of the connector. The inner peripheral portion of the connector is located interiorly of a caulking convex strip provided at an end face of one battery, and an inner peripheral portion is connected to the battery end face through welding without coming in contact with the caulking convex strip. The outer peripheral portion is connected to an outer peripheral portion of a battery end face of the other battery through welding.