A sealed prismatic battery has a battery case made of a plurality of prismatic cell cases coupled together via partition walls. Electrode plate groups are accommodated together with liquid electrolyte in each of the cell cases. Each electrode plate group consists of alternately stacked-up positive and negative electrode plates with separators interposed therebetween, lead portions of positive and negative electrode plates being protruded on opposite sides. Collectors are bonded to these lead portions. Between the collectors and end walls (and/or partition walls) of the battery case are provided conductive plates that are connected to the collectors one or more than one location in their middle part so as to decrease the resistance between connection terminals and the electrode plate groups.