I have found a solution for my iPhone battery life: recharge the mobile battery until reach 80 to 90% and stop to recharge. Do not recharge the battery all night long. Make a full recharge just once a month (IOS 6 User's Guide). It takes few days to see the improvements.
Restore your mobile for better improvements as well.
Hope it will be helpful
I know that we have experienced an Exchange connection issue Exchange (especially with the older Exchange servers) and Google. In my company, we have recommended that a user delete their email address and add it back again. Then restart their iPhone. This has addressed the issue many times incongunction with closing all multi-task apps. It seems that the handshake never completes and the iPhone is constantly stuck in a loop trying to complete it. By dropping and restarting it, it has helped almost every time.
Another setting you might consider limiting is Location Services. They can be big consumers depending upone what Apps are using them. Some are necessary and recommended and some are not. I would suggest you think about what are important to you. I hope this helps.