NOVELTY - The apparatus has a high voltage battery (9) comprising battery cells (1) including a current interrupt device that deforms to separate a connection point and cut-off current when battery cell internal pressure exceeds a set pressure. The interrupt device is connected to an electrode terminal and is placed between a pair of opposing planar surfaces. The cells are stacked with opposing planar surfaces opposite to each other to form a battery block (2). A pair of endplates (4) holds the cells in stacked configuration by applying pressure in a direction perpendicular to planar surfaces.    USE - Car power source apparatus for use in an electrically driven vehicle e.g. hybrid car or electric automobile, to supply power to a driving motor to drive the electrically driven vehicle.    ADVANTAGE - The apparatus improves battery safety with the current interrupt device housed in each battery to cut-off current when internal battery pressure rises abnormally while effectively preventing current interrupt device cut-off due to vehicle vibration. The apparatus prevents electrical contact between a case and the current interrupt device or the electrode unit while applying pressure to opposing planar surfaces of the case to retain the electrode unit and current interrupt device in a stationary fashion, so that the case can be retained with pressure applied to the opposing planar surfaces and detrimental effects such as battery cell internal short circuits can be prevented. The apparatus includes a deformable metal plate that deforms and separates from a connection metal to cut-off current when the battery cell internal pressure becomes greater than the set pressure, thus ensuring that the apparatus reliably cuts-off current when the internal battery cell pressure rises above the set pressure with the simple structured current interrupt device. The apparatus can prevent any movement due to electrode tab vibration by reliably retaining the electrode unit and the current interrupt device with pressure applied to opposing planar surfaces of the case, so that the separation of the connection region of the current interrupt device that is connected to the electrode tab can be effectively prevented.    DESCRIPTION OF DRAWING(S) - The drawing shows a side perspective view of a high voltage battery of a car power source apparatus.    Battery cells (1)    Battery block (2)    Endplates (4)    Connecting components (5)    High voltage battery (9)