Up until a few days ago, my battery would last over 13 hours before I would even need to charge it. I keep my data and WiFi off when not in use and haven't changed anything that should drain the battery more... the only thing I have going most of the time is my Charity Miles app, which I've used since getting my phone a couple months ago. Now I'm lucky if my phone goes 7 hours without being in the red... why the sudden death? I have the galaxy s7.