I met a buddy today who also has an iPhone5 and ios 6.1.3. He had 7 hours of usage, 1 day of standby logged and 65% battery life remaining. I'm unsure of how old the phone was but that works out to roughly 1.6% loss of battery per hour of usage, assuming 1% loss per hour of standby. Compared to my phone, that is stellar.
1 day = 24 hours, so 100% -24% = 76%, then the 7 hours of usage devided by 76%-65%= 11%/7 hours = 1.6% per hour usage.
My average battery usage was 1% per standby hour, and 10% per hour of normal usage!. That means everything from surfing the web, checking email, phone calls, or just looking at the screen. I would get anywhere from 4-6 hours of solid usage out of the phone and thats it.
When I first got the phone, I had a wicked battery drain after restoring it from an Iphone 4 backup. I did a DFU restore and it was purring like a kitten till the IOS 6.1.3 update.
I bit the bullet again, and just finished another DFU restore. I've restored my email/sync accounts as they were, and will be manually redownloading my apps, not restoring them from Itunes/Icloud backup. On the plus side I have lots of free space again for pics/movies. I'll update here with the results as soon as I can figure out how well (or not well) this worked.
Cheers