A rechargeable battery pack includes: a battery housing provided with an inner space; a series of unit battery cells accommodated in the inner space, each unit battery cell including a first electrode terminal and a second electrode terminal at respective upper and lower portions thereof; and a bus bar module electrically connected to the first electrode terminal and the second electrode terminal of each unit battery cell. The bus bar module may include a first bus bar electrically connected to the first electrode terminal at the upper portion of the unit battery cells, a second bus bar electrically connected to the second electrode terminal at the lower portion of the unit battery cells, and a connector part electrically connected to the first bus bar and the second bus bar.