Hi,
I've been having the same issue this past week. Just don't understand what is happening. It shuts down every day, even if the battery is over 50% before it dies. It is normally while flicking with the apps, or even in the middle of a phonecall...The most annoying thing is that when I plugg the charger, it starts and everything works fine. when I go to the battery graph it shows a drop from say 70% down to 40 % or from 30% down to 0 %. And again, there is now way to bring it back to life without the "jump start".
Is it soft/hardware or battery issue?
Have you found any solution to this?