Battery pack

1. A battery pack comprising:

a plurality of battery cells arranged in parallel with each other, each of the battery cells comprising an electrode terminal at opposite ends thereof;

a holder case configured to accommodate the battery cells;

a protection circuit module mounted at an external side of the holder case and comprising:

a main body; and

a cell voltage measuring terminal on the main body and facing the holder case; and

a connection tab comprising a body part electrically connected to the electrode terminals of a group of the battery cells and an extended part extended from the body part to contact and be electrically connected with the cell voltage measuring terminal of the protection circuit module due to tension in the extended part,

wherein the main body of the protection circuit module at least partially covers the extended part of the connection tab.

2. The battery pack of claim 1 , wherein the extended part comprises:

a first bent portion extended from the body part and bent from a surface parallel to the electrode terminals toward an external surface of the holder case;

a seating portion extended from the first bent portion and seated on the external surface of the holder case;

a second bent portion bent from the seating portion in a direction opposite to a bending direction of the first bent portion; and

a tension portion extended from the second bent portion and over the seating portion.

3. The battery pack of claim 2 , wherein the tension portion is spaced from the seating portion.

4. The battery pack of claim 2 , wherein the holder case comprises a guide part protruding in an upper direction along a periphery of the seating portion other than a region corresponding to the first bent portion.

5. The battery pack of claim 2 , wherein the connection tab comprises an insertion opening in the seating portion thereof.

6. The battery pack of claim 5 , wherein the holder case comprises a rib on the external surface of the holder case at a position corresponding to the insertion opening, and

wherein the rib is in the insertion opening.

7. The battery pack of claim 1 , wherein the holder case comprises a first fastening opening, and

wherein the protection circuit module comprises a second fastening opening corresponding to the first fastening opening such that the protection circuit module is fixed to the holder case by a fastening member passing through the first fastening opening and the second fastening opening.

8. The battery pack of claim 1 , wherein the holder case comprises a first holder case and a second holder case, each of which expose the electrode terminals of the battery cells and respectively extend over upper end surfaces and lower end surfaces of the battery cells.

9. The battery pack of claim 1 , further comprising a high current tab,

wherein the extended part of the connection tab is spaced from the high current tab.

10. The battery pack of claim 1 , wherein the extended part comprises:

a first bent portion extended from the body part and bent from a surface parallel to the electrode terminals toward the protection circuit module;

a seating portion extended from the first bent portion and seated on an external surface of the holder case;

a second bent portion bent from the seating portion toward the body part; and

a tension portion extended from the second bent portion and over the seating portion.

11. The battery pack of claim 1 , wherein the cell voltage measuring terminal in its entirety is located on the main body of the protection circuit module.

12. The battery pack of claim 1 , wherein the extended part and the cell voltage measuring terminal are connected to each other without being welded to each other.