does anybody have a pretty good general idea how battery life will be on this phone??? i have read in alot of reviews that this phone can get pretty good battery life (12-13 hrs) with moderate to some heavy use which i am pleased with, but at the same time i have heard ppl say that this phone has terrible battery life and will only last about 5 hours...so im just wondering what the real answer is and if anybody can help re assure me of the true battery life