NOVELTY - The apparatus (100) has a switching unit (10) turned-on at operating voltage. The switching unit is connected with a secondary battery (B). A fusing unit (20) blocks flow of excess current into the secondary battery that is provided with multiple battery cells. An electrode is connected with a first conductive plate. Another electrode is electrically connected with a second conductive plate. A third conductive plate is separated from the second conductive plate. A metal plate is equipped with another metal plate. A protrusion part is fixed to another protrusion part.    USE - Excess current blocking apparatus for use in a secondary battery e.g. lead accumulator, lithium battery, nickel-cadmium battery, nickel-metal hydride battery and nickel-zinc battery, of a battery module system of a battery pack system that is utilized by a portable electricity usage product e.g. digital video camera, mobile phone, power tool and laptop computer, a vehicle e.g. electric bicycle, electric vehicle and hybrid vehicle, and a bulk power storage system e.g. UPS (all claimed).    ADVANTAGE - The fusing unit blocks the flow of the excess current into the secondary battery and the switching unit is turned-on at the operating voltage so as to effectively avoid occurrence of swelling phenomenon i.e. short circuit, thus securing safety of the secondary battery.    DETAILED DESCRIPTION - The apparatus is provided with an alloy bridge part that is made of smokeless alloy material. The smokeless alloy material comprises 80-98 wt % of tin, 2-20 wt % of copper, nickel and zinc material. INDEPENDENT CLAIMS are also included for the following:    (1) a battery module system    (2) a battery pack system.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit block diagram of an excess current blocking apparatus.'(Drawing includes non-English language text)'    Secondary battery (B)    Exterior device (D)    Switching unit (10)    Fusing unit (20)    Excess current blocking apparatus (100)