More battery problems!

[Stan Marks]

I received the new battery (well, slightly used, actually) yesterday. Before
I installed it in my iBook, I checked the battery indicator on the bottom.
All four lights lit up.

I put the battery in the computer, and it ran the calculation routine, which
showed that it was charging, with about 30 minutes to achieve full charge.
Later, after it had charged up, I unplugged the power supply and took the
computer to another room to use. After about 3 minutes, the computer
suddenly went into sleep mode, with no warning, and showing a single
indicator light flashing!

When I plugged it back in, it ran through the calculation routine, again,
but this time it showed something like 7 hours to charge! Thinking that the
computer might be objecting to the new battery (?), I reset the PMU, again.
That seemed to straighten things out for a while, but the next time I
unplugged it, the usage time in the menu bar kept jumping back and
forth...like from 2 hours to 3 hours, etc., so I left the computer to charge
the battery overnight.

(I did check the settings in the Energy Saver preferences, which showed that
the computer was supposed to run for at least 10 minutes before initiating
sleep mode when on battery power, so that wasn't the problem.)

This morning, it showed a full charge on the battery, but when I unplugged
the power supply, again, it once more went to sleep with no warning after
about 3 minutes!

I'm far from any kind of expert with such things, but I'm beginning to get
the idea that the problem is not the battery...that something is screwed up
with my computer.

Any ideas/suggestions, before I call Apple Tech Support?

Stan