My Pismo battery (fairly new replacement) went kaput suddenly - and I have not been able to figure out why. A long story short, it seems that the battery's chip and the PMU (responsible for charging and reporting %) are not playing nice.
Pismo new battery flashing light then dead
Pismo new battery flashing light then dead (redirect)
PRAM battery has little to do with whether or not battery charges it seems, as one of the troubleshooting steps is to reset PRAM (did not help me)
My guess about the display brightness is PRAM related - "P" is "parameter" that user has chosen = brightness is a parameter
You will have the same problems FINDING batteries that Allan describes concerning the PC Card.
My strategy is to save any $$ I would spend on my PB in a cookie jar fund towards a new (refurb) Apple Notebook
You mention that your GOAL is to "transfer data"... if it were me, I would ask for advice on how to get that done with your current available gear and setup = tell is "transfer to WHAT device(s)"
- Ethernet transfer - network or peer-to-peer?
- upload > some cloud service > download to other device
When I get my new Mac, I will do a network file transfer.