I recently updated some drivers on my Ubuntu-based Linux Mint 16 Petra (sudo apt-get update and sudo apt-get dist-upgrade and such). Since the update, my power drivers have been acting funny and severely limiting my battery power. (NOTE: Before posting that I shouldn't be posting about Mint here, note that Linux Mint is Ubuntu-based and acts just like Ubuntu in nearly every way in terms of these low-level system and driver operations, which is where I believe the problem resides. Also, this forum is good and responsive while I have never had a single answer to any question I've ever posted on the Linux Mint forums.)

Since the update, the power manager underestimates my battery power 20-25% (and the charge stops increasing at 80%, though it still says that it's "charging") and it shuts down without warning and without any kind of shutdown procedures at 30-35% battery remaining. (When I say "without any kind of shutdown procedures", I mean that there is a small click and the screen goes black and all the lights just shut off like a switch was flipped; there's no program shutdown, no Linux Mint startup/shutdown icon, or any other indication that any kind of shutdown procedures are being activated.)

Because of this, I effectively have less than 50% of my normal battery life and no warnings to plug in my laptop to charge or shut down important programs before a system-wide shutdown. This is a serious issue.

If anyone can help me solve this, I would be very grateful.