I've got a G4 iBook that came in because the user thought the battery was dead. I tried the usual fixes, PMU, NVRAM, PRAM, different power adapter, etc. When I ran some tests (Coconut Battery) to see if the above worked, I found that the problem wasn't the battery (it still has 3888 mAh out of 4400). The symptom: The AC light alternates between green and amber even though the battery is only at 18% charge. It will stay amber for about 45 seconds then switch to green, vice-versa. It has been plugged in now for 2 hours + and has gone from 16% to 18%, so it does seem to be charging... I have adjusted the power saver so that the machine doesn't go to sleep or have the display dim as I thought sleep mode may have something to do with it. Any ideas?