I'm not understanding all these battery life issues. My 6S+ battery life is every bit as good as my old 6+ ever was and actually beats it, presumably because my 6+ was almost a year old. There must be something amiss somewhere, either to do with a backup or settings.
My phone's battery was dropping FAST on the first 2 days and I was getting the lock screen lock up. But since then battery life has stabilized; getting easily 2-3 hours of use on the first 10% of battery and the lock ups have stopped.
Could it have been indexing?