Is there a "normal" operating temp that the battery should be at? Obviously it's going to be alittle warmer if you're actively using the phone either just talking on it or multi tasking with various apps. When the phone is just sitting in my case, or charging up home out of the sunlight of course, is there such a thing as a normal temp? Ive noticed my resting phone to sometimes have a temp of 70 degrees and other times it's around 85? I use Batterylife, which incidentally works quite well as an accurate count of how much is remainig.