[cglad]

I've heard several variations on this theme, but was wondering if anyone had seen this behavior and knew of a fix.

Powerbook 15", purchased new in Nov 2005 -- runs fine on AC adapter, but as soon as it's unplugged and goes to battery, the screen goes black. System is still on --fan & lights running, but no screen. Owner has to do a hard shutdown (power button >10 seconds). System boots fine once AC power is re-applied.

Other tidbits:
Fully charged battery has dropped to 88% max
system has lost its time settings a couple of times
She reset the PMU -- didn't help

Questions/hunches:
Could this be a dead PRAM battery? (lost date & time settings)
Should the battery be fully discharged occasionally?
Could this just be a dead battery?

I know this is a little vague, but was hoping it rings a bell for someone. I haven't seen the machine yet, this is a verbal description from the owner, so I don't have many details. No Applecare, so obviously hoping for a cheap/easy fix.

Thanks

[Waragainstsleep]

Yes it could be a PRAM battery. Clock & date will reset if it is flat, but it could in theory be faulty too.
Could be the main battery at fault. I would test with another one to be certain.
Main battery should be run flat occasionally, then charged fully. This should recalibrate the charge meter.
It sounds like the main battery to me. Any Apple reseller should have a spare handy and be able to test it for you.