I have the above machine. I noticed that the it suddenly started using power, but only made the link to the 17.10 upgrade when I realised I was no longer getting battery low warnings which I had been getting with 16.? prior to upgrading. It also started switching off at 2 bars of power! I noticed this afternoon that it was not charging. Charge light not even showing.
Initially thought it might be that the plug was loose, but checked it and it was fine. I took the battery off, connected the cable and it ran fine on power. I watched an entire movie like that, with a pop up during the movie for various updates - which I authorised with my password.
Finished movie, restarted and it wouldn't do anything. Took cable out, put battery back and it booted up completely, put power cable in, as battery was at 20% and it died.
Now it boots on battery, but it is flat. Cannot make it work on power cable alone again. I am in the bush in South Sudan, so no IT techie, or shops around the corner! I am also quite technologically challenged!