I never had stellar battery life with any of my iPhones. But this last one takes the cake. It's a refurbished iPhone 6S I got from Apple after issues with the screen of my previous phone. My phone loses up to 30% battery overnight: - reset the phone without restoring from backup. I have about 20 apps. - all apps are force closed - background app refresh is OFF - no Location services except for System Services - Usage time states 2h overnight while I didn't touch it. I already went to the Apple Store and the diagnostics test didn't reveal anything, so the guy just proposed to always kill apps after using them and keep background refresh, location services as much OFF as possible, blabla. I assume his tests just check the capacity of the battery and that's fine. It's just that something keeps running in the background I guess. I frequently notice usage time and standby time are equal to each other as well. As I did a fresh install of 11.3 and have few apps, could it be a hardware issue? Any suggestions?