First of all: I have done all those PMU resetting stuff. The problem is that my iBook (1GHz, 768MB RAM, Tiger 10.4.3) keeps shutting off when I run it on battery. While plugged in there doesn't seem to be a problem. Here's what I've found out: This seems to happen only when I run the iBook from the battery There is no pattern as to when it will happen: It might be fully charged, at 70%, 50%, etc. There are no warnings: The iBook just dies To restart it I have to plug in the charger, I can't start it from the battery after one of these sudden deaths If I press the battery indicator after a crash, it doesn't show any charge - no green lights When I restart the machine the battery indicator will work, and it show's a charge in Tiger as well I've done all that PMU resetting, PRAM resetting, etc. Doesn't work. Any ideas as to what this could be? Bad battery? Any suggestions are most welcome One more thing: I've run the hardware test, and it doesn't come up with anything at all. Coconut Battery shows that my battery should hold a charge as well. Max charge is still at 3500mAh, 18 months and 750 cycles after I got the iBook.