PowerBooks/iBooks suddenly falling asleep: Not allowing full charge

On a number of occasions we've discussed an issue where PowerBooks and iBooks suddenly fall asleep with no low-battery warning, and while indicating varying levels of remaining charge.

A number of potential solutions have been reported, including calibrating the battery, resetting the PMU, using a battery monitoring utility, and simply leaving the PowerBook/iBook plugged in.

Now MacFixIt reader Merkley reports an additional workaround that might be successful for some users -- not allowing the battery to fully charge.

He writes "The battery indicator will go from 100% full charge to 0% randomly even if the Powerbook is plugged in. I have reset the PMU -- both by pushing the secret button and by booting into Open Firmware. This helps maybe 2% of the time. --- but here is what I have found ---- it's usually when the battery reaches a 100% full charge that it goes nuts and forgets that it is full -- if I unplug my computer when it registers 99% or less, it will give me the full 2 and a half hours of reliable use."

If you've found this method to be useful, please drop us a line at late-breakers@macfixit.com.

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