What makes LG G2 battery drains so fast ?

Over the last month I had the same problem. I found it was AT&T carrier IQ according to better battery stats app. It pushed me to install a custom rom (port from G3) onto my phone and now my battery is amazing. This past weekend I got 46 hours with light usage.
 
my lg g2 vs980 I've had for 7/8 months...at first the battery was like extremely good for the first two months ,I'd be at work all day and use it here in their wifi was on Bluetooth always on and it would be like 93%when I left work for a 10 hour day and I get up at 6...recently my screen broke and I had to order a new one and put it back home now the battery seems to be draining like crazy I don't know if that has anything to do with it or if it's just a coincidence but I know one thing I have to charge itat least twice a day sometimes 3 if I'm going out later. I've been through the battery I don't seem to see anything anybody have any ideas I recently unlocked the developer options right before the phone broke but didn't change any settings