Turning off overnight while on charge

view story

http://forum.xda-developers.com – Is there anyway to stop my S3 from turning off overnight while on charge? I use my phone all day so the battery is around 10%(ish) when I go to bed so I put it on charge and about 50% of the time my phone turns it's self off over night. I need my phone to stay on as I use it for an alarm. Is there any way to stop this? Is my S3 faulty? (HowTos)