I'm having the exact same problems with my notebook battery.
I'm very sure that is isn't a software problem, because i've swapped the hard drive and performed a fresh Windows installation.
I've also updated the BIOS of my notebook (PB E3255), but even that wasn't the solution.
So if it isn't the software, it's the hardware.
With this in mind, I began to brainstorm and i figured out this: The battery isn't dead of weak, but "he thinks" he is.
The solution to this problem is do completely discharge the battery, so that's what I'm doing now.
First Windows shutdown my notebook because the silly OS thought that the battery was running low (4% to go..).
After being shutdown, my notebook didn't want to start again because he still "thought" that the battery was empty.
So I took the battery out, and I've put it back in after 10 seconds.
After pressing the On button, the notebook boots up and keeps beeping that his battery is empty.
He's doing that now for the last 45 minuits until he's REALLY empty.
I'll post my results tonight, when I'm sertan that this is the sollution.
With kind regards,