Even a hairline crack can let dust and moisture into the time-keeping mechanism, threatening its accuracy. Unless the degree of water-resistance is clearly specified when you purchase your watch, do not wear it into the shower or pool, or on a moist wrist. Have a watchmaker or an authorized watch dealer replace the battery in a quartz watch before it runs out. Dead batteries left in the watch can leak or corrode, ruining the timepiece. Do not attempt to change the battery in a watch yourself.
Batteries run for about two to three years.
Those in some less expensive, multi-function digital watches have shorter lives, as little as six months. Using extra features such as a calculator or game can shorten battery life. Oils from your skin can build up on a watch. If your watch is water-resistant, you can give it a quick cleaning with a mixture of warm water and either a mild soap or a dish detergent. Dry the watch with a soft cloth after cleaning.