Battery pack with bus bar outside cell region

1. A battery pack, comprising:

a plurality of battery cells;

a circuit board electrically connecting the plurality of battery cells together, the circuit board extending along a first direction and a second direction; and

a bus bar connected to the circuit board to form a charge/discharge path, wherein the bus bar extends along a third direction, different from the first and second directions, and wherein the bus bar includes:

a body portion extending along the second direction, and

connection portions extending in the third direction from the body portion, the connection portions being spaced apart from each other along the second direction, each of the connection portions including connection protrusions separated from each other along the second direction by a recess, and a width of the recess in the second direction being smaller than a space between two adjacent connection portions in the second direction.

2. The battery pack as claimed in claim 1 , wherein the third direction is perpendicular to the circuit board.

3. The battery pack as claimed in claim 1 , wherein the bus bar extends along the second direction and has a dimension along the third direction that is greater than a dimension along the first direction.

4. The battery pack as claimed in claim 1 , wherein the body portion and the connection portions extend along the third direction.

5. The battery pack as claimed in claim 1 , wherein the connection portions are connected to respective connection holes in a cell region in which the battery cell is arranged.

6. The battery pack as claimed in claim 1 , wherein the bus bar further includes:

a bent portion extending in a bent form between the body portion and each of the connection portions to connect the body portion outside the cell region and each of the connection portions inside the cell region to each other, a single bent portion extending from the body portion to connect to the connection protrusions of a single one of the connection portions.

7. The battery pack as claimed in claim 5 , wherein:

the circuit board includes a first surface facing the battery cell and a second surface opposite to the first surface along the third direction, and

the connection portions are inserted into the connection holes in a direction facing from the first surface to the second surface of the circuit board, end portions of the connection protrusions protruding through the connection holes to extend above the second surface.

8. The battery pack as claimed in claim 5 , wherein the connection protrusions of a single one of the connection portions are inserted into a same one of the connection holes.

9. The battery pack as claimed in claim 8 , wherein the connection protrusions include a pair of connection protrusions separated from each other along the second direction by the recess.

10. The battery pack as claimed in claim 9 , wherein the recess accommodates a coupling material.

11. The battery pack as claimed in claim 5 , wherein each of the connection protrusions is individually inserted into a corresponding one of the connection holes in the circuit board.

12. The battery pack as claimed in claim 1 , wherein the bus bar includes first and second bus bars extending along first and second side portions of the circuit board that are opposite to each other along the first direction.

13. The battery pack as claimed in claim 12 , wherein:

the battery cells are arranged in first and second rows along the first direction,

the battery cells of first rows are biased toward the second side portion of the circuit board along the first direction to provide spaces for first connection holes between respective ones of the first rows and the first side portion of the circuit board, and

the battery cells of second rows are biased toward the first side portion of the circuit board along the first direction to provide spaces for second connection holes between respective ones of the second rows and the first side portion of the circuit board.

14. The battery pack as claimed in claim 13 , wherein the first bus bar is connected to the first connection holes, and the second bus bar is connected to the second connection holes.

15. The battery pack as claimed in claim 12 , wherein:

the circuit board is configured to electrically connect the plurality of battery cells in units of modules, adjacent first and second rows of battery cells forming one module,

the battery cells of first rows are biased toward the second side portion of the circuit board along the first direction to provide spaces for first connection holes between respective ones of the first rows and the first side portion of the circuit board, and

the battery cells of second rows are biased toward the first side portion of the circuit board along the first direction to provide spaces for second connection holes between respective ones of the second rows and the second side portion of the circuit board.

16. The battery pack as claimed in claim 15 , wherein the first bus bar is connected through the first connection holes and the second bus bar is connected through the second connection holes to first and second polarities of the module that are different from each other.

17. The battery pack as claimed in claim 1 , wherein the bus bar includes a cutout portion extending from a first end side close to an output terminal toward a second end side thereof.

18. The battery pack as claimed in claim 17 , wherein:

the cutout portion separates the first end side of the bus bar into a first region not directly connected to the output terminal and a second region directly connected to the output terminal, and

the first and second regions are electrically connected to each other through a third region outside the cutout portion.

19. The battery pack as claimed in claim 18 , wherein:

the first region includes a connection portion of the first end side connected to the circuit board, and

the second region is relatively farther from the circuit board along the third direction than the first region.

20. The battery pack as claimed in claim 1 , wherein the connection protrusions extend in the third direction, the recess extends in the third direction between facing sidewalls of adjacent ones of the connection protrusions, and the adjacent ones of the connection protrusions being connected to each other only via bottoms thereof.