Why won't it charge?

I recently updated my p9 and left it on power saving mode over night whilst it was not plugged in. In the morning I realised it had switched its self off and managed to turn it on for about 3 seconds before it died due to a 1% charge. After this i won't charge and when plugged into a computer a message pops up saying the device had malfunctioned. I think this is due to the power saving mode as I had no issues with the update before that and there was plenty of charge (about 70%) so it definitely shouldn't of gone down to 1% in the morning. Any ideas on what to do?