did you reset your phone after update
would u like to share what thing is consuming battery at first place.. Go to Device care tab > battery > battery usage
did u update all system apps of your phone ? we have to go ahead step by step..
well..... 25 % drop in battery = 2 hrs.
100% drop in battery = 8 hours (assuming)
it is not bad but average and you can improve it .
At first place, factory rest your phone after backing up data. resetting phone is the solution of many problems particularly after updating.
Secondly, turn off unnecessary features which use phone sensors. ( there may be 42 sensor related features in ur phone) Advance features > motions and gestures
turn off wifi and Bluetooth scanning along location if it is not in use.