I also encountered poor battery backup for few days. Like it would take 4 heavy use hours to come to 60 from 100. and then drop from 60 to 0 in one and half hour. but then I did recalibration as suggested by some people by full charging and discharging for 3 times. now it's been 2 weeks and I haven't faced that. also I keep killing tasks that I don't use by some cleaner app. And I uninstalled some pre-installed bloatware, and disabled others using app master. also keep shifting my photos n whatsapp videos to 32gb SD card. Now I am getting a good backup of 10-11 hours with 3-4 hours of calling and almost 4 hours of fiddling with some apps like news, surfing, WHATSAPP in half brightness which consumes 1.4-1.5gb of RAM. Especially this is performing brilliant on WiFi. it can manage 10 hours of WiFi easily. And 100 to 90 is really good. I just saw battery going down from 100 to 95 after a 4.5 hour call.
Actually standby is too good. so if I keep it on standby on 10% also, it may give me 3 hours easily.
If any of you can still help me improve the backup, I'm all ears.
