I have been monitoring my Iphone X battery life this week and it has gone down 5% in less than 1 week. It went from 100 to 99 to 96 to 95. Very surprised by this. Got the phone around January 1st of this year. Apple replaced it after I paid to have the 29 dollar battery put in right around Christmas on the one I bought when they first came out. They stripped the screws trying to replace battery so replaced with new one. So the phone is about 7 1/2 months old.