I've been having problems with my iPhone battery for over an year. My previous phone was an iPhone 4 running IOS 5.1. I tried every single idea I ever read about in a community forum, in a website, and stuff that other people simply suggested. Turning off location services, turning off Bluetooth, disabling or killing every application I was not using. I kept notifications to a minimum. I reset the network settings on my phone, erased and reinstalled all my e-mail accounts, and just plain reset it dozens of times.
Recently in a forum I read about a person that found a corrupt file that kept Safari on iOS running a loop,and therefore maintaining the processor busy and supposedly consuming more battery. He recommended not using Safari and using any other browser instead. However, this did not help my battery drainage problem. My phone was constantly hot. In order to help out a little I bought a Mophie battery case to help me get through the day with a powered phone.
I roughly calculated my battery to drain 1% for every two minutes and 20 seconds. So in just under two hours my battery would drain 50% simply being in standby.
I upgraded my iPhone 4 to iOS 6 in hopes that it would resolve my battery problem. I saw no change. About three weeks ago I bought an iPhone 5 and again hoped that this new hardware would not have the same battery problems I've been facing for over a year.
My three kids and wife all have iPhone 4s yet I was the only one having the battery problem. So this past weekend I was thinking what is it that I have in my phone that my kids and wife don't. It suddenly occurred to me that I am using a mail account that connects to a Microsoft Exchange 2003 server. So initially I deleted the account altogether to see if there would be any improvement.
I noticed very soon that my phone was getting cooler to the touch. And within half an hour I already knew that my battery was now draining at a normal rate. I tested further; I added the Exchange account again but this time I chose for the mail messages to be fetched rather then pushed to my iPhone. Again, I noticed that I was able to keep my mail account active and my battery was operating normally.
Finally, I configured the account once more for mail to be pushed. Within five minutes my phone got hot again and was once again draining my battery very quickly. So voilà! IFinally found the culprit of my predicament. It has to do with mailed being pushed to this account. I also have my iCloud mailbox active which is set to Push by default. It seems to have no problem with this.
I hope this helps people out there with the same problem. I would love to know if other people see the same results I saw.