Iphone 4S 8.1.1 Battery Problem
I have the same problem. Max life is 12 hours and very very little use.  It goes down by 5% per hour!!!

Apple said battery fine and I should only expect 10 to 12 hrs.  Back several iOS ago I could get well over 24 hours. 

Sounds like the want to force us to get new iPhones 6.