iPhone 5 battery draining after iOS 6.0.2 update even on standby mode without wifi/ 3G at all.

My newly bought iPhone 5 was on iOS 6.0.1

everything worked fine and i had no wifi nor battery issues at all until I upgraded it to iOS 6.0.

i noticed some battery drainage even when i'm not using my phone at all it still drains 1-2% on standby mode with no wifi nor 3G at all in an hour,

If i use wifi it'll drain 4-5% in a few minutes time, more serious case when i use 3G, it's literally draining in EVERY SINGLE MINUTE.