I have 2 iphone 6s, both received a new battery. One phone still runs 13.6.1 and the battery last 2-3 days depending on how much i use it. The second phone running 14.1 drains on standby in less than 8 hours!! It's doing nothing at all 100% at night and by morning phone is off with a dead battery. My working iphone goes with me into the field, it's going from data to wifi to no reception all day and still it last 2-3 days.. come on apple, this will be my last apple product if this isn't addressed soon! I've owned an Apple 6100, G3, G4, 2 ibooks, an ipad and they have all expired due to hardware issue or end of software support, even my G4(super computer!) has been outdated by Apple!