How long is lifetime of my watch battery?

A battery life varies usually from two to three years depending on the type of the watch, its dimensions and the amount of energy required by the different functions. For instance, a chronograph will have a higher energy consumption than a watch indicating the hours and minutes only.
Some movements feature a power preserve indicator: once the second hands starts moving in 4-seconds intervals, it is time to have the battery replaced by a Mondaine qualified watchmaker.