Abstract: On the opposite end walls of a flat, prismatic battery case of a battery module where electrode terminals are attached, protruding components are formed such as to protrude further than the electrode terminals. Terminal holes are formed in the end walls in which the electrode terminals are fitted, and the thickness of the end walls of the integral battery case in the vicinity of the terminal holes is not the same on both sides of each of the terminal holes. Also, one or a plurality of vertical and horizontal ribs are formed on the end walls between the electrode terminals and the protruding components. Further, a sealing structure is included for a battery.

Abstract: A rectangular electrode plate including a core metal sheet and a mixture paste coated thereon has a lead on one long side edge thereof where no mixture is coated, and a mixture non-coated part on the other side edge thereof. Positioning holes are punched only in the lead so that the stress exerted when punching the holes will not cause the mixture paste to fall off. Stacked electrode plates are accommodated within a magazine with a certain clearance between the three side edges of the electrodes other than the lead and the inner surface of the magazine, and fed one by one to be assembled into an electrode plate group to form a battery.

Abstract: A sealed rechargeable battery module wherein a safety vent device is provided to release the internal pressure of the battery when the pressure has reached a predetermined value. The safety vent device includes a valve case formed with a vent and a sealing protrusion surrounding this vent. A valve body inserted in the valve case includes a sealing portion that is brought in tight contact with the sealing protrusion, a rigid holder for supporting the sealing portion, a and a resilient portion for pressing the rigid holder toward the vent. A valve cover is formed with apertures for closing the upper open end of the valve case. In a state, the resilient portion of the valve body is compressed.

Abstract: A rectangular electrode plate including a core metal sheet and a mixture paste coated thereon has a lead on one long side edge thereof where no mixture is coated, and a mixture non-coated part on the other side edge thereof. Positioning holes are punched only in the lead so that the stress exerted when punching the holes will not cause the mixture paste to fall off. Stacked electrode plates are accommodated within a magazine with a certain clearance between the three side edges of the electrodes other than the lead and the inner surface of the magazine, and fed one by one to be assembled into an electrode plate group to form a battery.