battery readings on MB

My macbook is almost a month old, but I'm having problems with the battery estimation when unplugged. Sometimes it goes up instead of down (e.g. it's at 0:50, then 0:49, then 0:48, then 0:55). Sometimes it's way off (e.g. it reads 20% at 2:20 and then quickly drops to the correct #, say, 0:50).

Suggestions?

 

you MUST have never owned a windows PC before..
readings vary because depending on what you do on the comp you might ask for more or less ressource from the comp (also the brightness of your LCD, and other things..), thus you might be asking for more or less power from the battery, thus the battery readings will re-ajust itself accordingly.

but beleive me, macs have MUCH precise battery readings than PCs... can t even compare

 

I used to have an HP ZT3000, and from what I remember, the battery readings were VERY accurate, especially at the beginning.

 

I've never seen battery readings go up while unplugged, and I have owned Windows machines, too. Disregarding the indicated time remaining, does the battery run your MB a normal length of time? If so, I'd guess some sort of system glitch. Have you calibrated the battery yet?

 

It runs around anywhere from 2.5hours to 4 or 4.5, depending on what it's running. Haven't really timed it, so those are only estimations.

How doy ou calibrate a battery?

 

http://docs.info.apple.com/article.html?path=Mac/10.4/en/mh1959.html

 

k from what I've heard, these newer batteries don't need an initial calibration. I did it anyways, although I let my battery die (instructions for macbook that i just read say charge it when it's very very low).
And I recalibrate it every once in a while. Usually when I unplug it I let it go to 15% then recharge it, but once a month (around 15-20 charges) I recalibrate it, i.e. charge it when the bat is very very low.

 

Despite the indicator being haywire, battery life up to 4.5 hours sounds pretty good to me. I don't think my own MB lasted quite that long on battery power.

My MB must have been an older version with an older battery. It required calibration during the first week of its life, and needed to be run until it shut down (read: " . . . until it goes to 'sleep.'" The next step was to let it sleep for five hours before recharging. Thankfully, that only needed to be done once.

In any case, I hope your machine will now cooperate and indicate the actual percentage of life left in your battery.

 

THe thing is, it says 4.5 hours, but I doubt it runs for that long. I'll have to test it one day.