Series-coupling component for battery pack and battery pack

A series-coupling component for a battery pack, in a battery pack taking a cylindrical battery as a unit battery, the cylindrical battery including one convex electrode terminal at an upper end surface and another electrode terminal at a lower end surface, the coupling component being for holding two of the unit batteries coupled in series via a tab formed by folding a strip-shaped metal plate in a state where the two of the unit batteries are coaxially disposed,

• the coupling component being constituted of an integrated molded article made of resin,
• the coupling component comprising:
• a circular plate-shaped bulkhead portion;
• a cylinder portion taking the bulkhead portion as a top surface and opening downward, an upper end side of the unit battery being inserted into the cylinder portion;
• and
• a wall surface portion erected upwardly along a peripheral edge of the bulkhead portion to hold a lower end side of the unit battery,
• the wall surface portion being separated by a cutout portion from an upper end of a cylindrical side surface up to a top surface of the bulkhead portion at a part of the cylindrical side surface that opens at the upper side taking the bulkhead portion as a bottom,
• the bulkhead portion including a hole that communicates in an up and down direction at a center, and a groove having a rectangular cross-section on a top surface, the convex electrode terminal being inserted into the hole, the tab being housed in the groove,
• the groove extending in a radial direction of the circular plate-shaped bulkhead portion to open at peripheral edges of the hole and the bulkhead portion,
• the cutout portion being formed in a region that opens the groove at the peripheral edge of the bulkhead portion.