Patent ID: 7960052

Claim:
A battery module comprising: a plurality of batteries joined in a straight-line configuration, each of the batteries having a circular cylindrical shape defining a cylindrical outer side surface and end-planes at opposite ends thereof, the opposite end planes being formed as electrodes having different polarity, respectively; wherein the plurality of batteries includes at least a first battery and a second battery connected in series by a connecting part and an insulating cap for insulating the first and second batteries, wherein the insulating cap has an outer insulating region that covers portions of the outer side surfaces of the first and second batteries, and the connecting part comprises: a first welding section welded to the end-plane electrode of the first battery; a second welding section welded to the end-plane electrode of the second battery that opposes the end-plane of the first battery; and at least one welding terminal disposed on the outer insulating region of the insulating cap, wherein the outer insulating region of the insulating cap is positioned between the welding terminal of the connecting part and the outer side surface of one of the first and second batteries so that the welding terminal is insulated by the outer insulating region of the insulating cap from the outer side surface of the one of the first and second batteries.