I used to bring all my watches in for new batteries at the same time so all the batteries would die at the same time. Then, one day the guy changing the batteries said, pull the stem out (as if you are going to change the time) on the watches you don’t wear very often. When you pull the stem out, the battery stops drawing power. When you go to use that watch, push in the stem. For the watches you don’t wear very often, you will not need new batteries for a long, long time.