I have recently updated to iOS 8.1.2 from iOS 7.1.2 and every time I plug my phone into charger and leave it, it will switch off. It will still charge because when I unplug it, after a minute it switches back on with battery charged. If I use the phone whilst charger is plugged such as texting or internet surfing, the phone doesn't switch off. I would like to know if this is normal, is it something new Apple added to iOS 8 or is it only me? My iPhone is also jailbroken, as soon I updated to iOS 8.1.2, I then jailbroke it so I cannot tell whether it is the jailbreak the problem or the iOS 8.1.2 itself because I never used iOS 8.1.2 as vanilla. Any help will be useful, thanks.