Hi, I bought my iPhone in mid dec and had terrible battery issues. Standby was 9 hours, talk time was about 1 hour etc. I took it into the store to get it sorted out - the phone support was rubbish.
They diagnosed it as a software issue/bug. A sign was that the standby time and usage time appeared to be almost identical, indicating something was running in the background all the time.
They did a full reset - ie wipe the OS and reinstall as factory settings. Then he went tote settings, general and changed a bunch of the privacy settings al to OFF. There are about 6 or 7 on one tab, he turned them all off. Apparently in many cases they remain on and totally drain the battery.nthey have no mpact on location services etc (he showed me on his phone same settings applied)
Get full battery life now. Hope that helps.