This thread has resonances with the battle by beachycove to get a PB 500 series with a recelled battery to accept its new lease of life. I agree with wally's recommendation that rescue of a Rip van Powerbook begins with the backup battery. Small (in size and capacity), unseen inside the case, and crucial to the portability idea (ie, potentially independent of the AC mains) for PowerBooks.

Anything up to a week may be needed to get the backup battery back up, but even deeply-discharged batteries can be persuaded back into enough life for utility by the expenditure of nothing dearer than time on the AC adapter with no drain, ie not booted.

de