Really fast battery drain?

[AC Question]

So I have had a Sprint LG G3 for almost two years now. I have always had battery problems, but I never really asked anyone about it on forums. Until now of course. My G3 was running lollipop 5.11, and the battery life was horrible. I'd wake up at a 100% at 6:40, and it would stay at 100% until around 7:00. From there it would drop from about 100% to around 90 or 89% in about the minutes. I would turn off the phones screen, and after about another 10 minutes it would be at 81%. This is with the screen turned off. After about an hour and 30 minutes of class time, and me literally just downloading pictures, the battery would go down to about 60%. So from around 7:AM to 9:AM I'd have around 60% battery life while all of my friends have around 90% or more. I recently rooted the g3 and tried installing TWRP recovery. I failed, and soft bricked my phone. So I factory reset it, and then had the default g3 software on 4.4.2 kitkat. After some updates, I was able to get to lollipop 5.0.1. The next day I installed TWRP recovery, wiped the phone again, and installed a cm13 rom. Then I enabled root access once again. My standby battery is great now, and I cannot complain about it. However when I use the phones screen...the battery life is horrible. I tried disabling google services, swapping in a new battery, using multiple battery life apps, and lowering my screen brightness but it still loses battery really fast. The top section of the phone also gets really hot, around the camera area. I tried changing the CPU governor, but the phone still loses battery. When I set it to power saving governor, my standby battery was really good. It even went up 1%! However the second I would use the screen, the clock speed goes up to 1500mhz instead of the base 300mhz. I have it set to on demand right now. I am going to try to calibrate the battery today, and see if it solves any issues. Now my question is... do you guys have any possible solutions?

 

[Rukbat]

Downloading or any other activity that involves a transmitter (voice, text, internet) can be a huge battery drain if you have a weak signal. And the only "fix" is to use a carrier that has a strong signal where you need to use the phone. Check the battery in "Settings". Tap the graph and look at the bottom of that page, at the mobile data line. It should be green at home and at school.