MoveOn is a portable energy storage system charged by human motion. The goal is to create an energy support capable of supplying the user in circumstances of need or in places where mains supply does not reach. The product, conceived as a bracelet, stores elastic potential energy generated by the spring oscillation which is caused by the arm movement. Depending on the motion frequency, the power generated will be greater or lesser. This supposes that the range of motion frequencies and stored power varies for different activities and users. Basically, the energy harvested while running is greater than the one obtained walking, since the effort and the motion frequency of the arm are higher.