NOVELTY - A cell unit within a case (70) has flat batteries and insulating spacers that are stacked along a thickness direction of the batteries. Output terminals (140,150) for connecting the batteries are connected to the tabs of the electrode terminals received by and held between the spacers. The output terminals project outwards through the cutouts formed in a portion at the surrounding wall (71b) of a lower case (71). Insertion openings of the insulating covers provide a connection to an external device for detecting the voltage or controlling the charging or discharging of the batteries.    USE - For a vehicle such as a car or a train.    ADVANTAGE - The use of spacers or insulating plates to receive the electrode terminals or tabs of the batteries prevents the electrode terminals from being subjected to stress or fatigue caused by vibrations applied to the battery module. Dampening of vibrations by the use of the spacers improves the durability of the electrode terminals and the durability of the battery module. Using insulating plates to receive the electrode terminals prevents or reduces short-circuiting. When the instances of short-circuiting are reduced or prevented, a small vertical gap between the batteries and the terminals is allowed and the construction of a compact battery module is facilitated. A compact battery module with improved vibration resistance is provided. Because insulating spacers are located at both ends of batteries, exposure to the electrode terminals is reduced to ease the handling of the cell unit during the assembly of the battery module and to improve the quality. The battery modules are connected to form a battery assembly having a desired current, voltage and capacity to serve as a power source for a motor used to drive a vehicle. When assembled, the battery modules and their flat batteries are spaced from each other so that the space serves as a passageway for allowing the cooling air to cool each battery module and to prevent the degradation of battery charging efficiency by controlling its heat-degradation. By providing insertion openings in the insulating plate where the electrode terminals project, a portion of the electrode terminal is exposed that allows the dissipation of heat from the electrode terminal when charging or discharging a battery. The insertion openings prevent dew condensation on the electrode terminal resulting from repeated heating and cooling of the electrode terminals to prevent the erosion of the batteries.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the method of forming the battery module.    DESCRIPTION OF DRAWING(S) - The drawing shows the perspective view of a battery module.    Battery module (50)    Case (70)    Surrounding wall (71b)    Lower case (71)    Output terminals (140.150)