The purpose of the present invention is to provide simpler and more reliable electrical wiring than a lead wire. A battery pack includes at least one rechargeable secondary battery (1), a battery holder (70) for housing the secondary battery (1) in a predetermined position, a pack circuit board (74) having a mounted electronic circuit for monitoring the secondary battery (1), and an electrical connection wire (85) for electrically wiring the pack circuit board (74). Here, the electrical connection wire (85) is a bent metal wire. Because wiring is realized using metal wire, and the metal connection is secured after the wiring has been completed, movement and deformation due to vibrations and other factors, such as that which occurs in the case of conventional lead wires, are avoided, and reliability can be improved. Because the present invention has the simple configuration of a bent metal wire, manufacturing can be simplified, manufacturing costs can be reduced, and components requiring insulation to improve reliability can be reduced, thereby lowering material costs.