I had bad battery life for a week or something, even though I started from scratch with my iPhone 5S. When 7.0.3 came out I resetted settings, made a fresh iCloud backup, did DFU restore and used the backup. I then deleted all my accs (mail, FB etc.) and readded them. Another "Erase settings" and that's it. Seems better now:
20mins worth of calls (FaceTime Audio and cell), music, surfing the web (wifi and LTE), messaging, Facebook...
So it's basically 8h of usage, 30h of standby. That's fine, I guess.