How long can a coin cell battery last on an LED watch?

It depends on the current used by your product and the capacity of your battery. What is lithium coin cell battery? For example, your LED watch uses CR2032 (overseas Panasonic, Sony, Maxwell, domestic Mitsubishi The capacity of Xinhu, Lijia, Lixing and Golonda are 220 mAh and the capacity of Shenzhen Lidian battery is 240 mAh.) The operating current is 0.05 mA, then the operating time is 220/0.05 = 4400 hours, 240/0.05 = 4800 hours if the current is 0.01. mA, then the usage time is 220/0.01 = 22,000 hours, 240/0.01 = 24,000 hours. The battery storage life of these brands is around 5 years, that is if you use it 5 years ago. If the battery is produced. , even if it's new, it won't work! Usually, the watch battery is designed to work for more than 3 years! I hope this helped you!