I have just recently started getting this problem which is if I am using the laptop downstairs on the kitchen table for example I can be in the middle of doing something on the laptop when it suddenly turns off even though it is 85% charged.I then press the power button and it starts to come on then turns off again.This can happen wherever I am using the laptop but do not get it when it is plugged in.Any advice appreciated.The laptop is not plugged in when this happens