This is not only an issue with the the Z2. I have an original Z Force and I have been having this same problem for the past couple of months. I came to this forum to see if anyone else had found a solution for it, but I see that is not the case. I am ready to throw my phone through a wall. It cuts off all the time, once when I was about to use it to pay for my items at a store, and I didn't have my credit card with me because I always use my phone. I had plenty of battery power left, but it would not restart until I got back in the car and plugged it in!! This is more than a slight inconvenience. I have been with Verizon for almost 20 years and I have another year left on my contract, but I am ready to pay the penalty just because I am so over this.