Mechanical self-winding watches use wrist movement to wind the mainspring and power the watch. They appeal to buyers who enjoy traditional watchmaking, visible engineering and the experience of a movement that works without a disposable battery.Power reserve, wearing habits and movement care affect how long an automatic watch runs when removed. If a watch stops after it has not been worn, it may simply need winding and resetting rather than repair.Read why automatic watches stop and compare movement types in our automatic vs quartz guide.