Concerned 3 I just got it yesterday, so I don't know about the battery life yet. Sleep mode works fine. But, it drags as I try to move it around on the screen and sometimes the curser stops following me and then disappears from the spot where it stopped and reappears where I moved to. Not happy with this mouse. It has a nice look and feel, but operationally poor quality. I don't recommend it. Now I have to buy something different. It was a waste of money.