I bought my iPhone 4 two-tree months ago, but was a used phone so in total its around 1 year old. When I bought it, it already had IOS 5.01 installed on it. I use my phone every single day at work for music, and the iPod app runs 9 hours in a row, occasially using facebook in between. If I had charged my phone to 100% all night, then the phone would have around 50-60% left when I left work, which was perfect. Suddenly two weeks ago my battery went crazy! After only using the iPod app for 2 hours, it would have dropped 30%! My phone completely dies after about 6 hours play now. Whats even more strange, is that if its only on standby with nothing turned on, it will last a whole night without charging and only dropped 2%. It's jailbroken if that matters... I jailbroke it almost complete after the jailbreak come out, but this problem only started a week ago. Any ideas? PS... headline was supposed to say "Sudden"