Disclosed herein is a battery module having a plurality of unit cells that can be charged and discharged, the battery module including busbars for electrically interconnecting the unit cells, ring terminals connected to electrical connection portions of the unit cells for measuring voltages of the unit cells, and a busbar mounting member mounted at an outer surface of the battery module corresponding to the electrical connection portions of the unit cells, the busbar mounting member including ring terminal guides for preventing rotation of the ring terminals.