Toshiba Satellite L645 - Battery Not Charging

Hello, I am new to the forums, and I hope I’m in the right place to look for help. If not, please accept my sincerest apologies.

I have a Toshiba Satellite L645 (Model No. PSKOGU) laptop. I am running it dual booted - Ubuntu MATE 14.04 and Win 7. With the laptop powered off, running Win 7, or running a live USB of Ubuntu MATE 14.04 the battery charges as expected. However, if I run off the Ubuntu MATE 14.04 partition on the hard drive, the battery fails to charge. If the battery is already charged, I can unplug the charger and the laptop will continue to run until the battery dies. But if I plug the charger back in, the battery continues to drain as though it isn’t plugged in (and it will even die with the charger plugged in).

I have scoured the Ubuntu forums, but I can’t find recent information. And the information I have found doesn’t really seem to match the symptoms I’ve been experiencing. So I’m reaching out to see if anyone can explain why the battery will charge while running off the live USB, but not off the hard drive.

Thank you in advance to anyone willing and able to help.