Charge the battery (overnight works) fully. Unplug system. Let it run until it sleeps - when I got my TiBook, I had probably 45 minutes past "0%" on the battery the first time. Recharge battery.

So yes, it runs a bit hotter, but probably not enough to affect the long-term health of my PowerBook. Battery life also seems to be largely unaffected.

I'd like to upgrade to a MacBook Pro and sell my Powerbook G4 (last gen before Intel... 1.5GB Ram, ~1.5 years of Applecare left). I use the battery a lot all the time, and after 300 cycles, it's ...