I own the iPhone 5 that i got on Dec. 1 , 2013. Since owning this thing I would drain 1% every 4 to 7 minutes of STANDBY. I've been to the apple store 3 times, they wiped it twice and the third time they set mail to fetch manually. The problem still is happening, the phone drains like crazy in standby.
I've given up on going to the apple store as they won't do nothing because the hardware test says my battery is perfect and so is all the other hardware on the phone.
After messing around with my settings and turning every thing off and doing the draining of the battery til it shuts off I've found one setting that helps to give me normal battery life. If i turn off cellular data I get the battery life I should when the phone is in standby. This is not really a fix more like a band-aid, but at least i can go a day on standby and still have battery left.
It sucks hearing about how everyone else is getting a day or two of standby when i only get half that at most. The crazy part is that when i do have cellular data on I get about 3 to 4 bars and NEVER get 1 or 2 bars. I have Virgin mobile and never had this problem with the Android phones I had in the past.