A seatbelt system for generating electrical energy. The seatbelt system includes a rewinding mechanism, an electrical generation mechanism, a locking mechanism, and a charging mechanism. A first rotational engagement unit of the rewinding mechanism is rotated by the movement of a seatbelt and in turn rotates a second rotational engagement unit. The rotation of the second rotational engagement unit causes the electrical generation mechanism to generate electrical energy. The charging mechanism may charge a battery with the generated electrical energy.