battery life topic

hello my very intelligent mob

i have stock standard rom and not rooted LG G3 phone

my battery life barely lasts a day and my phone heats to about 42 degrees

how do i finding out the nawti app causing this first world drama in my life?

are there simple steps to root the phone use these so called custom ROM's?

im 4.4.2 version V10o-AME-XX

i'm scared to update to lollipop despite of the ota notification because of all the bugs and issues

I use battery guru by snapdragon and that seems to help a lil

any help would be helpful thanks