My iPhone's battery does not retain its power?

I had on August 1 Gig 3G iPhone since September 8 and I have not had any problems with it until a few days ago when I would charge my phone through the night, he is 100% of the battery, can I go to school without using it. i whole school would not use it (I have not been much, so it's not) and end of the day, it is 20%. I do not have anything more, such as 3G enabled, and my mother is very happy not to be able to join. also my phone does not work with its charger normal and does not connect to iTunes, even when it is supported on the computer and synchronized images in any help would be greatly appreciated. Thank you! and I can not reset it because the button / Sleep is broken.

This is a problem battery so that you may want to go into an Apple store so they can replace it or tell you what to do. One way to keep it charged for more off the things you do not. Disable wifi, bluetooth, and 3G. If you do not use it during the day while they should not be on because they just waste battery. Additionally, 3G will not make a big difference unless you're surfing the web. If you are just sending SMS or phone calls, there is no reason to be on 3G. I would definitely go to an Apple Store but because they will be able to tell you what to do or give you a replacement. Hope that helps.

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