Lg g4 battery HELP

Hello guys i dont know if it is posted already but , im having problems with my battery life im using my phone for a couple of weeks now. I tried to factory reset my phone but still, i also installed greenify to see if it is because of an app but NO. Basically i find that sometimes the battery peecentage drains so rapidly without me doing anything on the phone with my brightness at 0% and all other stuff like gps, sync etc turned off. Also another big problem is that the battery percentages skips i may be using my phone at 88% but suddenly it goes down to 84% thats really dissapointing.

I have heard people praise about the battery life of this phone which is one of the reason i bought it but now its not what i expected especially with the skips.

If you guys can help me do anything I would really appreciate it.

Thanks