Here is a link to a very good method for recalibrating the skyrockets battery reporting. I am unrooted so I have used the bottom method. The batteries in our phones don't have a "memory" like the old NiCads did, but the battery level reporting mechanism will get out of whack every 30-60 recharge cycles. This method and the one recommended by Apple for the iPhone seem to work well for me(let your phone run down completely once a month or so according to Apple). YMMV. I am recharging my phone today after getting over 28 hours, over 4 hours of screen-on time and all kinds of Rocket loving goodness including watching the whole movie Unforgiven, and still having 20% left...no Juice Destroyer either...check it out if your results aren't what you think they should be.