In the past few weeks, my iPhone 6 has been shutting off always with over 15% battery life. Oddly, this has happened 3 times when I get a text from Verizon that I have "x%" data remaining. I have no internet at home so I've been a heavy data user - I do, however, have a 24GB plan, so I don't exceed that. I'm wondering if the crashing has something to do with Verizon throttling bandwidth because my speed is always a little slower afterward? Maybe just a faulty battery?