System for auto-exchanging of electric vehicle battery

Disclosed is a system (200) for automatically exchanging a battery (B) of an electric vehicle (2), an electric battery (B) being mounted on a side of an upper portion of the vehicle (2), the system including a horizontal frame (120) of a predetermined area formed at a location higher than the electric vehicle (2); a plurality of battery stands (250) formed on a bottom surface of the horizontal frame (120) at a predetermined interval; a pair of fixed guide rails (210) arranged and installed on front and rear sides or left and right sides of the horizontal frame (120), respectively; a variable guide rail (220) adapted to move horizontally along X-axis or Y-axis along the fixed guide rails (210); a movable rail (230) adapted to move horizontally along Y-axis or X-axis along the variable guide rail (220) and ascend/descend vertically; and a grasping means (240) installed on a lower end of the movable rail (230) and adapted to pick up a battery (B) of the electric vehicle (2) or a battery (B) seated on the battery stand (250) and exchange each other. A nearly discharged battery (B), which is mounted on the battery mounting recess (10) of an electric vehicle (2), is easily exchanged with one of fully-charged batteries (B) stored on a loader, which is installed on a bus stop, for example, within a short period of time, thereby substantially improving efficiency.