calibrating the battery question

i bought my macbook pro last july, and since july, i calibrated my battery once a month, and since i had a powerbook before, i calibrated my macbook pro battery now just like how i calibrated my powerbook battery before... so last night, i drained my battery to zero, so it would eventually go to sleep as usual, and the warning came, saying that "you are running on low battery" as usual but instead of sleeping it shuts down.. i have to turn the power button on again, and plug it in the power. so my question is, is something wrong with my mbp? is it suppose to sleep when the battery reaches zero? but why did my mbp shuts down last night instead of sleeping? it only happens last night only, but before that, it always go to sleep... and my second question, i've been doing the powerbook method of calibrating the battery, but last night, i just saw in the apple website that, the macbook pros have new method of calibrating its battery which is,......

PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), MacBook Pro (all models), and MacBook Pro (17-inch) (all models)

The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery released with this computer. With these computers, follow these steps to calibrate your battery:

Plug in the power adapter and fully charge your PowerBook's battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
Disconnect the power adapter with the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, you will see the low battery warning dialog on the screen.
Continue to keep your computer on until it goes to sleep. Save all your work and close all applications when the battery gets very low, before the computer goes to sleep.
Turn off the computer or allow it to sleep for five hours or more.
Connect the power adapter and leave it connected until the battery is fully charged again.

so i've been doing the powerbook method of calibrating my battery since july, which is i plug the power as soon as my macbook pro goes to sleep,... is there something wrong? would it harm my macbook pro?

and now the health of my battery is 99%.

 

I would not worry too much about the 99%, my 12 cycle battery has 95% so its no big deal i think.

Just keep in mind that it will flactuate a little bit since it is not so accurate.

 

That is fine, what happened there was your battery was almost nearly 100% drained out, and the Mac saved what you were last doing onto the RAM (to prevent you from losing data), so when you pressed the Power button again it returns to what you were last doing.

And battery health indicators are never 100% perfect. 99% is fine. Next thing you know, in a few days it might go back up to 100% .

 

my battery health is 95% after 82 cycles...how come yours is only at 12 and its at 95%?

 

like he said its not that accurate
mine is 22% and at 239 cycles, aren't they suppose to last 300 cycles b4 they die? But @ 239 cycles mines pretty dead already.

 

Hmm, you do have a Powerbook so that may differ, but according to Apple, after 300 cycles the battery should be at 80% battery health.

 

wow 300 cycles and at 80%, batteries sure do last a long time nowadays.
I got my powerbook in 2003 and had to replace my battery in 2005 and now I need a new battery pack again since I only get about 30 min of run time. However, I recently came across the battery exchange program !!! ( I was searching for online stores that have the battery pack in stock, I was prepared to purchase a new battery pack). Anyways Apple shipped the battery pack yesterday and it should arrive on friday!!

 

In my never-ending quest to promote Apple Forum efficiency here is a redirection for anyone who wants more information on the Powerbook 12inch Battery Exchange.

 

Sorry to resurrect a month old thread, but I figured it was better than making a new one. So is the consensus that dropping 2-3% in battery health after 5 or so charges is normal? I calibrated my battery first thing when I got my MBP following the instructions on Apple's page exactly. At first the battery health showed as 99%. Now after about 4 cycles it's down to 97%. Maybe it's me but that seems like a big drop.

 

Yeai think it should be fine. Mine went to like 95 after 10~ cycles, and stayed at that for like 20 cycles.
Then it went up to 96 for about another 20, and now its back to 95%. So I think it should be fine.

 

That sounds completely normal.

I went from 6-9 cycles and stayed at 96% Health over the past several weeks. Now iStat Pro reads 100% Health (still at 9 cycles) and I didn't even calibrate the battery. It's definitely not a perfect measure.

 

Alright, thanks guys. That's a load off my mind.

 

The battery health indicators aren't accurate...I had the same thing that happened to Xander happen to me.

First I calibrated my MacBook battery, and the battery health went to 96%. I just ignored it and a week later it showed that it went back to 100%.

As long as its not a dramatic drop (say to 80-85%), then your battery is okay.