I decided to investigate my iBook’s weak battery. After not quite two years, it appears to have lost almost 90% of its charge (748 / 4400 = 0.17).
"IOBatteryInfo" = ({"Capacity"=748,"Amperage"=443,"CycleCount"=552,"Current"=596,"Voltage"=12598,"Flags"=838860807,"AbsoluteMaxCapacity"=4400})
This translates to being able to work for 4 hours on battery to about 40 minutes.
Looks like I need to find a good source for a battery as well. They seem to run about $100.
<update: Thu Oct 6 21:55:35 PDT 2005 > just scored one on ebay for $40, new in box.