Abstract: Disclosed herein is a plate-shaped secondary battery used as a unit cell for middle- or large-sized battery pack, the secondary battery having an electrode assembly, which can be charged and discharged, mounted in a sheet-shaped battery case including a metal layer and a resin layer in a sealed state, the electrode assembly having electrode terminals protruding outside a sealing part of the battery case, wherein at least one of the electrode terminals is provided at a position spaced a predetermined distance from the sealing part with a self cutting part having a vertical sectional area less than that of the remaining part of the at least one electrode terminal such that the self cutting part can break first when overcurrent flows in the secondary battery.

Abstract: Disclosed herein is a plate-shaped secondary battery used as a unit cell for middle- or large-sized battery pack, the secondary battery having an electrode assembly, which can be charged and discharged, mounted in a sheet-shaped battery case including a metal layer and a resin layer in a sealed state, the electrode assembly having electrode terminals protruding outside a sealing part of the battery case, wherein at least one of the electrode terminals is provided at a position spaced a predetermined distance from the sealing part with a self cutting part having a vertical sectional area less than that of the remaining part of the at least one electrode terminal such that the self cutting part can break first when overcurrent flows in the secondary battery.

Abstract: Embodiments of the present invention are directed to a method and apparatus for multiple battery cell management. In one embodiment, a solid state relay is used instead of a mechanical relay in a BMS. The SSR is smaller and faster than a mechanical relay, enabling smaller BMSs that more efficiently and safely manage battery cell charge. In another embodiment, a plurality of battery cells are connected to two rails, using four SSRs to control access to the battery cells. In one embodiment, a plurality of battery cells are grouped together and controlled as one module of a multi-module BMS. In one embodiment, each module has 10 battery cells in series. In one embodiment, the BMS controls 4 modules. In one embodiment, each module is controlled by control signals passing through logical gates. In another embodiment, each module is controlled by control signals passing through a programmed circuit.