Tired of loose batteries rolling around at the bottom of your camera bag? never sure which ones are charged? Then this is the simple answer... pop charged batteries in the case with the tops facing away from the case hinge. When you have used them, put them back in the case with the tops facing the case hinge so you know they need charging. The cases are semi-transparent so you don't need to open the case to check the state of the batteries inside. Almost too simple...