The invention provides a soft pack battery module and its electricity supply thereof. The battery units, which are independent and complete modules, are utilized to be contacted to each other to form the battery cell with the serial connection, the parallel connection or both. There only have charges transferred rather than electrochemical reactions occurred between the battery units. Also, the metallized plastic film package is utilized to pack the battery cell. The inner electrically-conductive area of the metallized plastic film package is directly contacted to the electric power outputs of the battery cell to form electrical connections. Therefore, the problems caused by the need for additional wires can be avoided and the surface area the current path of the battery cell can be maximized.