How long does a CMOS battery typically last?

The typical lifespan of a CMOS battery ranges often between 2 to 10 years, depending largely on usage, the specific battery type, and the environment in which the computer operates. Choosing 3 years as the answer provides a reasonable average estimate, aligning with many manufacturers' data suggesting that most CMOS batteries last around this time frame under normal conditions.

CMOS batteries are crucial for keeping BIOS settings and the system clock running when the computer is powered off. While a battery might last less than 3 years in a system that is frequently turned off for long periods, many batteries can indeed last longer than 3 years, sometimes up to 5 years or more in use. However, without specifying beyond such averages, 3 years remains a practical choice that reflects common real-world scenarios adequately.