Battery draining too fast after 50%

[iamdchosen1]

This is an issue I've observed from the past few days, as soon as the battery reaches 50%, it starts draining rapidly. Till that I get 3h 30 min of screen on time and currently I'm on 15% and screen on time is 5h.
I am on stock OOS 7.1.1 ( not on the latest beta) , stock kernel, unlocked bootloader.
Only Facebook and whatsapp are the only heavy apps I use.
I have attached screenshots for convenience.
Please help.

 

[Balino]

I don't see nothing strange from the screenshots. 5h sot doesn't look bad at all too

Sent from my OnePlus 3T using XDA Labs

 

[domsch1988]

Also, notice how from 50% your screen is on pretty much constantly. Before it wasn't. The drop in battery seems to correspond with your screen beeing on, which is normal