Patent ID: 8110302

Claim:
A battery pack comprising: at least one unit comprising a plurality of batteries and a first connector for connecting the batteries in parallel; and a second connector interconnected to the first connector for connecting the unit to an external terminal or another battery or unit in series, wherein the first connector has a current collection region to which positive terminals or negative terminals of the batteries are connected and a connection portion connected to the second connector, the current collection region is divided in two regions: (i) a distant region which is distant from the connection portion for a predetermined value or more in a direction parallel to a current collection direction; and (ii) a close region which is distant from the connection portion for less than the predetermined value in the direction parallel to the current collection direction, the close region having the same area as the distant region, and the electrical resistance R 1 of the distant region per unit length in the current collection direction is larger than the electrical resistance R 2 of the close region per unit length in the current collection direction.