Origineel bericht door: Aleksandra ,
This happens to my Sony phone too, usually when I use an app for longer period of time, common errors in the android system,basically what happens is your phone shuts down to prevent any further battery damage. Have you tried upgrading the version of android you have? Or it may be due to you force closing apps ( running services) to clear your RAM? For now I would suggest don't leave any apps running for long period of time.