Generating device of vehicle

A generating device of vehicle installed on a car body's bottom and comprising:

• at least a fastening device installed on said car body's bottom;
• at least a girder joining said fastening device for vertical movement;
• at least a strut fixed at said girder far away from said fastening device;
• at least an alternator under said girder;
• at least a roller joining said strut far away from said girder, contacting ground surfaces, and oscillating vertically with said roller;
• at least a battery electrically connected to said alternator;
• characterized in that said rollers and said girders driven by a running vehicle oscillate vertically and said girders oscillating downward transmit kinetic energy to said alternators in which kinetic energy is constantly transformed to electric energy stored in said batteries.