I get 10min of heavy use. I am thinking about getting the mungen battery. Heavy use in my opinion is googl tlk and using the browser. Any type of voip program on my n810 will kill the battery in no time flat. I would like to know is there something OS or APP related killing the battery or is it just a short life battery. I have had the oem battery that comes with the n810 since its realease or about two years. I have never had a cell phone battery do this so why are the batteries in the n810 acting this way.