Provided is a battery pack in which the production of heat due to passage of current in a connector for connecting secondary batteries in parallel is made uniform to increase service life and reduce maintenance costs. A positive terminal connector 14 comprises a connector 14 with through-holes 18. The connector 14 is divided into two regions: a distant region which is distant from the portion connected to an external terminal; and a close region which is close to the connection portion and has the same area as the distant region. The connector 14 is formed so that the open area ratio of the distant region is greater than that of the close region. Thus, the electrical resistance of the close region can be made smaller than that of the distant region. Therefore, the production of heat due to passage of current in the close region can be suppressed.