Abstract: A battery pack comprises a cylindrical rechargeable battery, an electronic circuit board including a charging circuit to charge the battery, and being electrically connected to the battery, a cylindrical case incorporating the battery and the electric circuit board, and having openings at both ends thereof, and having a positive terminal and a negative terminal in the openings to discharge the battery, and having a hole in a recess portion at the peripheral surface thereof, and a connector port being disposed at the peripheral surface, and being fixed to the electrical circuit board, and an insertion opening of the connector ports being exposed through the hole at the peripheral surface of the case.

Abstract: In a battery pack (1),a current loop between the positive and negative electrode plates of an electrode assembly passes points P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13 and P14 in this order. A line that connects P2 to P3 intersects a line that connects P11 to P12 in the part where the loop passes a sealing plate (12), which is arranged on the top of a battery unit (10). The loop can be divided into loop parts B1 and B2. The part B1 is formed on the exterior side of the battery unit, and extends from the intersection A through a circuit board (20) back to the intersection A. The part B2 is formed on the interior side of the battery unit relative to the intersection A. The current flows counterclockwise and clockwise in the parts B1 and B2, respectively.

Abstract: In a battery pack (1), a current loop between the positive and negative electrode plates of an electrode assembly passes points P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13 and P14 in this order. A line that connects P2 to P3 intersects a line that connects P11 to P12 in the part where the loop passes a sealing plate (12), which is arranged on the top of a battery unit (10). The loop can be divided into loop parts B1 and B2. The part B1 is formed on the exterior side of the battery unit, and extends from the intersection A through a circuit board (20) back to the intersection A. The part B2 is formed on the interior side of the battery unit relative to the intersection A. The current flows counterclockwise and clockwise in the parts B1 and B2, respectively.

Abstract: The nonaqueous electrolyte used in the nonaqueous electrolyte battery of the invention is characterized in that it contains vinylene carbonate (VC) and lithium borofluoride (LiBF4) and further contains at least one derivative selected from among cycloalkylbenzene derivatives or from among alkylbenzene derivatives having a quaternary carbon atom directly bound to the benzene ring and having no primary or secondary alkyl group directly bound to the benzene ring. The use of such nonaqueous electrolyte makes the storage characteristics of the nonaqueous electrolyte battery at high temperature improve remarkably even when the content of LiBF4 is reduced, while preventing diminution of battery capacity at the same time.