I have the Razer Mamba 2012 mouse on a Mac Mini 2011 edition, for some strange reason it never stops recharging?!? No matter if I use the charger dock or the cable directly in it, the green LEDs on the side always light up. I am pretty sure it stopped lighting on my old 2010 Mac when it was charged, or do I remember wrong? Is something wrong with my mouse?? Have to say, have at the moment not installed the Razer drivers as the mouse is already setup via the old Mac (wich I have now sold). Would it help if I installed the driver?
Install the drivers anyway. Unless you notice the battery life seems shorter than it used to be than I think it's nothing to worry about; it may well be that without the software & drivers installed the pc can't communicate with the mouse at an advanced level to tell it when to turn the lights off, so they just stay on by default...