Anyone noticed that battery duration depends on how many Apple apps you use? I was a heavy Whatsapp, Google Maps and Spotify user and my iPhone battery used to die around 5 pm, but a month ago moved to the US and switched to iMessage and Apple Maps using the same functions of those apps and now my battery finishes day with 40%. Same with Spotify and Apple Music. Anyone knows why this happen? Is this normal? Excuse my bad english, I'm foreign student.