Battery capacity dropping with 'reserve battery power'

[stagmeister]

Hi,

So I have a 15" 1.5ghz PB, and it has been an excellent computer. However recently, I forgot to plug in my computer in and when it said that there was about 30 minutes left on the battery, all of a sudden it dropped to 1%, announced that it was on 'reserve battery power,' and that I should either shut down the computer or plug it in before it automatically went to sleep. Now I know this is something that happens when you let the battery run down--like you are supposed to do to keep the battery calibrated. However, after examining the situation with CoconutBattery, it seems that the battery capacity itself has dropped 6% or so (this has happened twice so apparently I have 88% of the original battery capacity). Has anyone else run into similar problems, or is this something normal? I would rather not end up with near to no battery life as that is what makes a laptop useful.

Jason

 

[Angrist]

The battery will lose capacity as it ages. This should'nt have anything to do with the fact that it just fully drained (i think).

I have a 20 month old PowerBook and I'm down to about 68% of the original capacity. I've noticed this number drop when I fully discharge the battery too .... but not every time I drain the battery, and not only when I drain the battery (sometimes it happens at full charge). Which leads me to think that the battery has lost it's capacity during the course of use, and the battery monitoring software only updates capacity at fully drained or fully charged.