This is a great value for 100 batteries. I realize why they sell so many. I use these in our touchless Kohler toilet. I've had to change them every 3 weeks. It's about 2.5 weeks if you count the number of times we have had to hover our hand over the sensor before it would flush. The battery life is terrible. We have 3 toliets in the house, so these batteries die even when they are not being used.