Battery Meter Inaccuracy on Powerbook G4

[Maciej]

Well fellas, I have a 15" PB G4, 1.25 Ghz, 512 MB of ram, and running 10.3.4. Recently I have noticed that when my battery provides me with the estimated time of power remaining, it is slightly inaccurate. Once the clock counts down to 1 minute, it remains there for up to 15 minutes, at 0% battery remaining. Is there any way to reset this? I fear it might have come about from lack of discharging the battery for the last couple weeks. I've been trying to do it often to reprogram the firmware responsible for the battery reading, but of no luck right now.

Any suggestions and contributions will be much appreciated!

[DMBand0026]

Try resetting your PMU.

Info on how to do that can be found here (http://docs.info.apple.com/article.html?artnum=14449)

That will most likely solve your problem. If not, try letting the power run out totally, than recharge all the way a few times.

[Maciej]

Yeah, I just reset the PMU a couple days ago for a Bluetooth problem. Can you be more precise with what you mean by "letting the power run out totally?" The closest to this I can imagine is just letting it run until the PB dies and will not come out of sleep mode, but I still know there is power because the small light on the latch is on...

[DMBand0026]

That's exactly it. Run until it forces itself to go to sleep, than charge fully. Rinse and repeat. :)

Should recalibrate your battery and have your battery meter working like it should in no time flat.

[Maciej]

Wonderful, thanks for the help DMB.

[Escher]

Wonderful, thanks for the help DMB.

Sh0eWax: Let me also point you to Apple's official Battery Page (http://www.apple.com/batteries/), which mentions that "rinse and repeat" is unnecessary. You only need to discharge your battery fully (until automatic sleep) once to calibrate it.

Escher

[Wrao]

I had the same problem with mine recently, and it's a pretty gnarly story.

about 4 months ago, my battery went from excellent(3 hours average) to barely adequate(1:40 hours or so) it did this in about ONE DAY!

I've lived with it fine, since I rarely have my 'book unplugged for a long enough time for it to be a problem.

Recently though, my power adaptor broke, so I had to buy a new one. I figured, that would be a good time to Re-calibrate the battery, so I let the battery drain out all the way.

Now, the weird thing is, I got to 1% battery left, and it said I had 1 minute left. But the computer just stayed on. Didn't goto sleep, just chilled there.

I decided to turn some music on to help drain the battery faster, then me and my roommate went to In n Out burger, and returned nearly an hour later. My computer was asleep, I asked my roommate if he knew when it went to sleep and he said "not too long ago"

I plugged it in, and opened it up, it woke back up and showed my last iChat window and said that I logged out almost exactly a full hour after I said "my battery is about to run out any second now, see you later"

:eek:

Obviously I was super stoked, I thought that maybe, this whole time my battery had just been calibrated incorrectly, and that I really was still getting 3 hours of juice, but it was only telling me about 1:40 worth. But alas, when I plugged in and charged to full, it still tells me I only have about 1:40, and when I tried to drain it again, it went to sleep shortly after it hit 0% :(


I do have a question relating to this though, how was my computer able to have a full hour of juice left after the meter said it was empty AND while I was playing music out of it? :\