These batteries are not long life (span.) So you usually get about a day per charge and it seems you are getting that. On smart phones the battery time is affected by what apps you install.
Ad driven apps tend to eat battery time so to see if it's that, you eject (uninstall) all apps. There are thousands of web pages about this so you must use all the advice given to date.
So half a year ago I bought a Samsung Galaxy S7 Edge and now that I am finally back in school I started noticing that my battery depletes like.. really fast!! even after only 4 hours of minimum use I am already on 66%