Kinetic watches transform the kinetic energy of movement into electrical energy, using that energy to run the mechanism of the timepiece, according to Seiko. A weight inside the watch moves whenever you move your wrist, spinning a tiny generator to create current. This electricity runs the mechanism of the watch and eliminates the need for replaceable batteries or winding.
Unlike self-winding watches, which use kinetic energy to re-wind the tension spring mechanism that keeps the timepiece running, kinetic watches involve electricity. Stored electricity conducts through a quartz crystal, creating a vibration that maintains the timing of the gears inside the watch. Quartz timepieces are more accurate than mechanical ones, losing only a few seconds over the course of a month rather than minutes. Miniaturization and technological advances have reduced the amount of power needed to run this system to a micro-watt or less, making it possible to generate this electricity simply through incidental body movements. If a kinetic watch remains stationary for a long period of time, the internal battery may run out of power to run the mechanism, but simply shaking the watch for a few moments should introduce enough charge into the system to get things running again.