Hitachi, Ltd.

Hitachi Automotive Systems, Ltd.

Hitachi Vehicle Energy, Ltd.

Masuhiro Onishi

Yoshihisa Tsurumi

Kinya Aota

Susumu Harada

Seiichi Sato

Shoji Imanaga

A battery pack with a reduced resistance connection arrangement in which battery cells are arranged in rows in an insulating case and an electrode of each battery cell is coupled to an electrode of another battery cell through a connecting metallic plate. The connecting metallic plate is made of copper and is disposed on a positive electrode of one battery cell and a negative electrode of another battery cell to form a lap joint. Welds are formed in predetermined positions on the connecting metallic plate above the positive and negative electrodes by arc spot welding. The electrodes are formed of nickel-coated steel. The depth h of weld penetration in the weld is greater than the thickness Tof the connecting metallic plate and smaller than the thickness Tplus the thickness Tof one of the electrodes, that is, T&#x3c;h&#x2266;(T+T&#xd7;4/5).

Battery pack and method for welding cells

A battery module is configured so that the first cell string and the second cell string are arranged between the first plate member and the second plate member and the second cell string is arranged closer to the second plate member side than the first cell string is and is arranged closer to the outlet side than the first cell string is. At the inlet side of the housing, the inlet is arranged closer to the first plate member than to the second cell string, at least a part between the inlet side of the second cell string and the second plate member is covered by the inlet-side guide plate, and the cooling air is introduced into the housing through the inlet so as to form a flow of the cooling air along the first plate member and a flow of the cooling air along the inlet-side guide plate.

Battery module, electric storage device and electric system

Growing community of inventors

Uji, Japan

Masuhiro Onishi