The battery life of individual quartz watches generally falls between 1 to 3 years. Given that the power consumption of the IC circuit in early quartz watches was extremely low (approximately 1 microamp), this significantly extended the battery life of these watches. For watches with three hands (including a second hand), when not in use, you can pull out the crown to stop the motor from running, which is commonly referred to as the watch's power-saving function. If you don't plan on using your watch for a short period, it's recommended to pull out the crown.
However, for quartz watches that are not used for a long time, some issues need attention. Long term refers to exceeding the battery's expiration date. It’s important to know that most quartz watches use silver oxide batteries, and like other types of batteries, silver oxide batteries self-discharge even when not in use (such as during storage). The rate of self-discharge is closely related to the environmental temperature and humidity; higher temperatures increase the self-discharge rate.
Some silver oxide batteries are prone to alkali creep and leakage problems, especially those with poor quality and inadequate sealing. These issues often occur when the battery is nearly or completely drained. This phenomenon is similar to regular dry batteries. Silver oxide batteries contain alkaline electrolytes, usually sodium hydroxide or potassium hydroxide, both of which are highly corrosive. Once they leak, they can cause significant damage to the watch. First, they can corrode the spring contacts of the watch circuit; secondly, severe leakage can also corrode the movement plates of the watch, and in the worst cases, damage the watch dial. I once had a Radar watch that was stored unused for about 10 years, and later found that the battery had leaked, causing corrosion and discoloration near the battery on the dial. It cost me around 700 yuan to replace the dial, a lesson learned the hard way!
There are many examples of items damaged by batteries, not just watches. For instance, dry batteries in flashlights, if left unused for a long time, can swell after being depleted (silver oxide batteries have a similar problem called "gas swelling") and become impossible to remove. Imagine if this happened inside a camera—it would be disastrous.
Therefore, I recommend that if you have a quartz watch that will not be used for a long time, especially a more expensive one, it's best to take it to a repair shop and have the battery removed to prevent accidents. When replacing the battery, always choose high-quality branded batteries. For those who are meticulous, it's advisable to replace the battery periodically (not necessarily waiting until the battery is completely drained). Remember, a significant proportion of quartz watch malfunctions are caused by battery-related issues.