Bus bar module

A bus bar module configured to be attached to a battery assembly having a plurality of single cells which are assembled to each other along a first direction, the bus bar module comprising:

• a circuit body configured by a flexible board on which a wiring pattern is provided;
• a bus bar configured to be connected to an electrode of each of the single cells;
• and
• a holder configured to hold the bus bar and being stretchable and shrinkable in the first direction,
• wherein the circuit body includes:
• a main line that extends in the first direction;
• a branch line that extends from the main line so as to branch from the main line, a part of the branch line extending in the first direction and including a folded portion having a shape folded back around an axis extending in a width direction of the part of the branch line and intersecting with the first direction;
• and
• a connection portion provided in a position closer to a distal end of the branch line than the folded portion and configured to be connected to the bus bar;
• and
• wherein the main line and the branch line are configured by a unity member of the flexible board having a multiplicity of circuit structures;
• wherein the branch line includes:
• a first branch portion extending from a side portion of the main line in a direction intersecting with the first direction of the main line;
• and
• a second branch portion connecting with and extending from each of the first branch portion and to the connection portion;
• wherein the second branch portion having the folded portion and a constant width, the constant width of the second branch portion is measured in the width direction, and the width direction is perpendicular to both of the first direction and a thickness direction of the main line;
• and
• wherein the constant width of the second branch portion is the same as a width of the connection portion measured in the width direction.