Taken from /.
For more info see: https://depot.info.apple.com/batteryexchange/index.html
If you have a Powerbook G4 15" and your battery's serial number starts HQ404, HQ405, HQ406, HQ407 or HQ408 then you could be at risk of it overheating.
For more info see: https://depot.info.apple.com/batteryexchange/index.html