TIL 24308 (removing PowerBook batteries) states that "In the time between removing the first battery and inserting the second battery, the PowerBook is using the backup lithium battery to power the RAM. If you have a large RAM card that draws an excessive amount of power, the RAM card can drain the backup battery before the second main battery is inserted. This can also happen with a smaller RAM card that is faulty. In each case, the PowerBook may shut down and be unable to start up until it is connected to AC power."
Apple Memory Guide 12/97 is now out.
Apple's Mac OS 8.1 page is stating that the update will not be out until February.