I wrote about a problem that how quickly became out of juice of butteries of an imac cordless mouse on this blog. Then I got a great answer from one of readers. She said "When you don't use it turn off a switch behind the mouse. That reminded me that when I got the imac, there was a instruction something like that. Actually, I was doing it at that time. But it was not easy kept doing that. So, I stopped it and I forgot the instruction. However, to save energy I have to make effort. Also, it good to save money.