What exactly is CPU use under android os? I also have badass battery monitor and my kernel goes up to 30% That's what's been killing my battery a lot lately though, CPU use. I have no idea what it is but i think its the culprit for battery drain when idol and when being used. On a day when that's not an issue my phone can go a day no problem at all. But when that's an issue I have to charge it twice.