Battery pack

A battery pack, comprising:

• a plurality of battery cells;
• a first case accommodating the plurality of battery cells;
• a protection circuit module coupled to one side of the plurality of battery cells and electrically connecting the plurality of battery cells;
• a bus bar electrically connected to the protection circuit module and extending in one direction along the plurality of battery cells;
• and
• a second case coupled to the first case and accommodating the plurality of battery cells, the protection circuit module, and the bus bar,
• wherein the bus bar includes a slit extending inwardly in the one direction from one end thereof to a divergence point that is located a distance from the end of the bus bar that is about ¼ to ⅓ of a total length of the bus bar in the one direction to form a diverged branch of the bus bar.