A pressure vessel for pressurized secondary cells is disclosed. The vessel includes a generally cylindrical container having both ends closed by substantially flat circular discs. The container has a diameter dimension substantially greater than its axial dimension. A mechanism is provided for supporting a plurality of substantially rectangular stacked electrode plates within the container. A pair of sealed terminal connectors pass through the container, and a terminal assembly mechanism is disposed within the container for directly interconnecting the stacked plates to each terminal connector.