Just like everyone else on here I'm constantly monitoring my battery and trying to figure out what hurts it and what helps but I give up. Yesterday my phone said it was running 20% of the time with almost no app/phone usage and my battery was at 20% after 12 hours. Today my phone says it's been on 100% of the time with bluetooth on for 50% and after 13 hours it's still at 51% battery left. I've tried every stupid widget and app to try and find out what works best and I've come to the conclusion IT'S IMPOSSIBLE. The eris has its good days and its bad days and I'll never figure out why. Oh.. and today I didn't do the airplane trick so I also had 50% without signal. Makes no sense.