Thank you for using Apple Support Communities!
I would recommend that you take a look at these troubleshooting steps in the article named iPhone: Hardware troubleshooting found here http://support.apple.com/kb/TS2802.
- Click ( www.apple.com/batteries/iphone.html) for tips on how to prolong iPhone's battery life.
- Try turning iPhone off and then on again.
- Connect iPhone to iTunes and restore iPhone.
- If the screen shows a low-battery image, the battery is low on power and needs to charge for up to ten minutes before you can use it.
- When charging iPhone, make sure to leave it charging until it is fully charged. You'll know the battery is fully charged when the battery icon in the upper-right corner of the screen looks like this .
Note: When charging using a computer, don't connect iPhone to a keyboard. Also, the computer must be turned on and not in sleep or standby mode. If iPhone is connected to a computer that's not turned on or is in sleep or standby mode, the iPhone battery may drain.
All the very best,