A battery having an electrode unit in which edges of electrode plates are
mechanically and electrically connected to a fixing and conducting plate
is obtained. A projection is formed at an edge of each electrode plate,
and projections are inserted into a grove formed on the fixing and
conducting plate. Energy beam is radiated to the fixing and conducting
plate along a wall defining the groove, and metal forming the groove is
melted and fills a gap between the projection and the groove. The filling
metal is solidified at a condition that the melted metal surrounds the
projection. The electrode plate is firmly connected to the fixing and
conducting plate by a combination of the projection and the surrounding
metal. The electrode plates are stably maintained at a positional
relationship that the electrode plates extend parallel with each other
leaving a gap between adjacent electrode plates, and the electrode plates
are connected to the fixing and conducting plate with a reliable electric
conductivity.