I think that what I am experiencing is a battery going bad. I have been using the machine a lot lately unplugged from the wall. Whereas I used to get about 4 hours (when the battery was new), I am getting only about three hours now. But, I am also heavily using the Airport card.
But, what concerns me more is the fact that sometimes the battery does not seem to charge I will leave the Power Book plugged into the power supply overnight, and in the morning the battery will show less then an hour of time available.
I have reset the PMU by using the reset button on the back of the machine, and that did not seem to help.
So, what do you think? A bad battery, or something more serious? Buying a new battery is not that big a deal, but I wold liek to feel that this is the right move.
I am talking to myself here, but....
The other thing that I have noticed is erratic charging behaviour. I have the battery status displayed on the status bar. Often, instead of the number of minutes till full charge (when charging), or the number of minutes till dead battery (wehn running from battery), it will say "calculating". It will leave this calculating message up for a long time. I have noticed it in particular when the battery was nearly dead and I started to try to charge it. In this case, the percentage also seems to hover below abou 3% for a long time. Once the percentage charge gets over 5% to 10%, the time till full charge works again.
Again, this all sounds like a dying battery to me, but I'd like to hear what other prople think before I just buy a new battery.