iOS 9.21 iphone 6 draining battery seriously

On 5th Feb 2016 finally i update my iphone 6 software to ios 9.2.1 after i read some note from website say ios 9.2 have some malicious problem.. so im update..after one night with ios 9.2.1, i feel my iphone getting hot on back side.. And i see my battery level drop almost 40% without using.. i see on setting->battery standby mode only 4hours but battery drain so fast after update.. I already do full restore with itunes and set up new phone without restore previous backup.. The problem still remains ..after few hour research i found some tips, say restore previous backup, but nothing changed, its still same. I never found this problem with previous update..but this is my first time i face it.. Apple doesn't not really test the new software before release it.. I hope incoming update iOS 9.3 this problem solve.. I cant downgrade anymore to iOS 9.2 because apple has stop signin the firmware.. my iphone now getting worst and useless cant stay over 3 hours after full charger.. if use LTE connection battery drain 1 min 1% and backsides iphone feel hot