Wind-up, or mechanical, watches use a spring mechanism rather than a battery to keep accurate time. They come in a wide variety of styles and may offer additional features and complications like a date window or moon dial. While quartz watches are much more common today, wind-up watches still have several distinct advantages.
One of the biggest advantages of a mechanical watch is its lack of a battery. This means the watch will never stop running due to a dead battery, and will work even if it has been stored for an extended period of time; all it will need is a fresh wind of the mechanism. Wind-up watches eliminate the need to buy batteries and pay for their replacement while also reducing the amount of waste from dead watch batteries being thrown away.
There are two different types of wind-up mechanical watches. The first are standard winding watches, which the owner must wind once or twice each day. The second type is a self-winding, or automatic, watch. These watches require no winding and receive their energy from the natural motion of the arm wearing the watch. Self-winding watches are the most convenient option, never needing batteries or even manual winding to keep accurate time.
Wind-up watches and clocks predate battery-powered watches by centuries. These devices use traditional engineering methods and come from some of the finest watchmakers, including highly desirable luxury brands. Some of the most expensive watches in the world are self-winding models from European jewelers, though low-end wind-up watches are priced competitively with quartz models.
On the surface, wind-up watches look very similar to battery-powered watches. However, some feature see-through glass enclosures or glass backs to show off the complex inner mechanism, including the springs, gears and rocking escapement. Wind-up watches also make a constant, soft "tick, tock" sound as they run, which is another advantage to some watch owners.