Battery pack

摘要

A battery pack includes first battery blocks 21, a core block 20, a plate-shaped circuit board 30, and a case 10. Each battery block 21 includes batteries 26. The core block 20 includes the battery blocks 21 aligned in the longitudinal direction. The circuit board 30 includes a discharging control circuit. The case 10 accommodates said core block 20 and the circuit board 30, and has a sectionally symmetrical tubular shape. The batteries are classified into curvedly-arranged and centrally-arranged groups 27B and 27A. In a cross-sectional view of said case 10, the batteries in the curvedly-arranged group 27B are arranged vertically along curved side surfaces of said tube. The batteries in centrally-arranged group 27A are arranged vertically substantially in a straight line. The centrally-arranged group 27A is arranged lower than the curvedly-arranged group 27B. The circuit board 30 is arranged above the centrally-arranged group 27A.