NOVELTY - A battery comprises multiple flat type batteries, each comprising outer sheath and electric power generating component. The outer sheath has a composite laminate film made of polymer and metal. The electric power generating component is accommodated and hermetically sealed in the outer sheath by compelling at least a part of the circumference of the outer sheath to be joined by thermal welding to form thermally welded portions.    USE - Used for vehicles (claimed) and hybrid cars.    ADVANTAGE - The battery has higher energy density and power output while having reduced weight. It includes an outer sheath that provides improved reliability in a sealing property to alloy the unit cells to improve charging and discharging performance in the large electric current capacity.    DETAILED DESCRIPTION - A battery comprises multiple flat type batteries (1), each having outer sheath (3), electric power generating component, positive electrode terminal lead (8) and negative electrode terminal lead (9). The outer sheath has a composite laminate film made of polymer and metal. The electric power generating component includes positive electrode plate, a separator and negative electrode plate. It is accommodated and hermetically sealed in the outer sheath by compelling at least a part of the circumference of the outer sheath to be joined by thermal welding to form thermally welded portions (2). The positive electrode terminal lead is conductive with the positive electrode plate and held between the thermally welded portions to be exposed to an outside of the outer sheath. The negative electrode terminal lead is conductive with negative electrode plate and held between the thermally welded portions to be exposed to the outside of the outer sheath. The positive electrode terminal lead and/or negative electrode terminal lead has surface covering layer made of metal different from that of a terminal mother material of the positive electrode terminal lead and the negative electrode terminal lead. A connector member is electrically connecting the flat type batteries to one another.    An INDEPENDENT CLAIM is also included for manufacturing of battery comprising preparing flat type batteries and electrically connecting the flat type batteries to one another.    DESCRIPTION OF DRAWING(S) - The drawing shows the flat type battery.    Flat type batteries (1)    Thermally welded portions (2)    Outer sheath (3)    Positive electrode terminal lead (8)    Negative electrode terminal lead (9)