broken battery / pram on pb5300?

the second I pull the power cord, the machine dies. It also fails to keep pram settings when you do this.
Zaren Ankleweed wrote on :

Okay. so I recently swapped a 5300cs motherboard into my 190cs, and things were fine. I installed os9 and wireless software for a wavelan card, and things were fine. I was eking out about an hour and a half on a charge, which I figured was pretty damned good for an original issue pb190 / 5300 battery. But then...

I installed a larger hard drive - a whole gig, instead of the original 500 meg! To make a long story short, the drive appears to be bad. During the process of confirming this, however, my battery stopped supplying power to the system - the second I pull the power cord, the machine dies. It also fails to keep pram settings when you do this. The pram settings stay around between restarts if you power cord stays connected.

An attempt to zap pram during startup results in an instant power down of the system. The system will not power up at all unless the power cord is plugged in, and when I do plug it in, it powers up on it's own - no touching a power key is nessicary. I'm using VST's expansion bay power supply, if that makes any difference. The power board that plugs into the motherboard appears to be connected properly and undamaged. Oh, and i just tried to run Battery Recondition on the machine... as soon was I confirmed that it was okay to recondition, the power died to the machine. :p

Any clues / hints / suggestions on what might be wrong, or how to fix this? I was just getting used to lugging this thing around fully untethered; having to keep it plugged in would suck.