Actually i had seen a big improvement on my previous phone battery once samsung had released the oreo update, i don't know what feature is inside it but it definitely gave me a few extra hours.
not sure if it would work the same on this phone tho.

Hey, i had some fun recently by rooting my P10000 pro and making a custom interface for the device. Check this video to see what it looks like : https://youtu.be/3lAc8Go6iAo i took the stock interface apk and cutomized it with my own logo and added a bit of code to unlock brightness slider, cutomize...