A system for protecting a device having variable internal resistance includes a protection fuse capable of blowing when a current having an intensity greater than an intensity threshold passes through. The system also includes an estimator suitable for estimating the internal resistance of the device, and a safety device suitable for limiting and/or preventing use of the device when the internal resistance is greater than a resistance threshold beyond which the protection fuse is inoperative.

A battery module and an energy storage device including a battery rack including a plurality of battery modules, and a rack fuse cutting off a circuit when an overcurrent occurs in the battery rack, each of the plurality of battery modules includes a battery cell and a module fuse that cuts off a circuit when an overcurrent occurs in the battery module, the module fuse has a voltage specification capable of corresponding to an output voltage of the battery rack, and has a short circuit specification lower than a short circuit specification of the rack fuse.

A battery module and an energy storage device including a battery rack including a plurality of battery modules, and a rack fuse cutting off a circuit when an overcurrent occurs in the battery rack, each of the plurality of battery modules includes a battery cell and a module fuse that cuts off a circuit when an overcurrent occurs in the battery module, the module fuse has a voltage specification capable of corresponding to an output voltage of the battery rack, and has a short circuit specification lower than a short circuit specification of the rack fuse.

The present invention relates to a secondary battery which is capable of improving safety. As an example, a secondary battery which comprises an electrode assembly; a case which accommodates the electrode assembly; a cap assembly which is coupled to an upper portion of the case, and a gasket which is interposed between the cap assembly and the case, wherein the cap assembly comprises a cap-up, a safety vent which is installed at a lower portion of the cap-up, a cap-down which is installed at a lower portion of the safety vent, an insulator which is interposed between the safety vent and the cap-down, and a sub-plate which is located on a lower surface of the cap-down, and an insulation layer is formed on one surface of the safety vent, is disclosed.

A power supply apparatus includes a battery pack for an electric vehicle, and an interface unit that couples the battery pack and a plurality of electrical devices. The interface unit includes a branch connector provided with a coupling unit and a plurality of fuses. The coupling unit allows coupling wires to join. Each of the coupling wires is coupled to a corresponding one of electrical devices. Each of the plurality of fuses is disposed in a corresponding one of coupling wires. The interface unit also includes a battery pack connector that is able to be coupled to the branch connector. In a state in which the branch connector is coupled to the battery pack connector, the power supply apparatus is configured to be able to supply electric power from the battery pack to each of the plurality of electrical devices via the coupling unit.

A battery pack includes at least one battery unit. The battery unit includes at least one battery string. The battery string includes one or at least two cells. A voltage difference across the battery string is less than or equal to 60 V. When the battery string includes at least two cells, the cells in the battery string are arranged sequentially along a first direction, and the first direction is parallel to a direction from the tail of the vehicle to the head of the vehicle.

A battery pack includes at least one battery unit. The battery unit includes at least one battery string. The battery string includes one or at least two cells. A voltage difference across the battery string is less than or equal to 60 V. When the battery string includes at least two cells, the cells in the battery string are arranged sequentially along a first direction, and the first direction is parallel to a direction from the tail of the vehicle to the head of the vehicle.

A battery module includes a plurality of cylindrical battery cells having electrode terminals; a module housing having an inner space to accommodate the cylindrical battery cells; and a module bus bar configured to electrically connect the cylindrical battery cells to each other. The module bus bar includes a first metal plate having a first body portion facing an outer surface of the module housing and a first contact portion configured to contact the electrode terminal; and a second metal plate having a second body portion stacked on an outer side of the first body portion of the first metal plate, a second contact portion configured to contact the electrode terminal, and a fuse portion configured to electrically connect the second contact portion and the second body portion and be disconnected at a predetermined current or above. The second metal plate has a smaller thickness than the first metal plate.

A battery pack has a fuse box bracket for short circuit prevention, and more particularly a battery pack configured such that two or more unit modules are electrically connected to each other, the battery pack including a fuse interposed between connection terminals extending from the unit modules; and a fuse box bracket located under the fuse, wherein the fuse includes a central portion made of a nonconductor and an edge portion made of a conductor.

A battery pack has a fuse box bracket for short circuit prevention, and more particularly a battery pack configured such that two or more unit modules are electrically connected to each other, the battery pack including a fuse interposed between connection terminals extending from the unit modules; and a fuse box bracket located under the fuse, wherein the fuse includes a central portion made of a nonconductor and an edge portion made of a conductor.