battery calibration

[maryannemoll]

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hi. my iBook G3's battery must be showing signs of long use. everytime it's fully charged, it shows 2:30 on the bar. isn't it supposed to be 5 hours?

anyway, i used to be able to watch an entire movie on my ibook on the bus to bicol when it's fully charged. now, i can't even finish an hour watching before it issues a warning about battery time left.

i tried calibrating it. dapat use it until it shuts down, right? it doesn't shut down, actually, it just goes to sleep. when i try to wake it up, it won't. hence i thought that was already equivalent to a shutdown na. i charged it, but still it's at 2:30 when fully charged. I never calibrated it when i bought it. i never even knew a battery had to be calibrated. when i picked it up at LMK, everything was already installed because i didn't know how to install then anyway.

do i need a new battery? i need to be able to watch movies on a single charge. did i calibrate properly?

thanks, peeps.

[maryannemoll]

in addition, when it was new, it shows 3:10 when fully charged. it never showed 5 hours on the bar, ever since.

[maryannemoll]

also, is it a good practice to keep the ibook plugged in even after it has already been fully charged?

[Adel]

Apple's slightly exaggerated claims are largely for effect only. That predicted battery life is only if things were perfect; reality is much different. Although your effective battery life is a bit on the low side, actually.

Leaving it plugged in after being fully charged shouldn't hurt. The charger 'trickles' power enough to top off the battery, and keeps it at 100% or as close to it as possible, without it being harmful.

Your iBook G3 is running right about on schedule. I have one and its battery gives me about two hours on a good day, 1.5 hours otherwise. Time to change, but make sure you buy the most recently manufactured one you can buy; the seller might say it's brand-new, unused and unopened, but if its an old unit, the power rating would still be low.

More info from Apple KB #86284:


PowerBook G4 and iBook: How to Calibrate a New Battery for Best Performance


TOPIC
This document explains how to calibrate your new iBook or PowerBook G4 Lithium Ion battery for best performance.


DISCUSSION
The battery of an iBook or PowerBook G4 computer has an internal microprocessor that provides an estimate of the amount of energy in the battery during charging and discharging. The battery needs to be recalibrated from time to time to keep the onscreen battery time and percent display accurate. You should perform this procedure when you first use your computer and then every couple of months thereafter.

Follow these steps:
1. Plug the power adapter in and fully charge your iBook or PowerBook G4 computer's battery until the battery indicator lights turn off and the adapter plug ring goes from amber to green, which indicates that the battery is fully charged.

2. Disconnect the power adapter and use your iBook or PowerBook G4 computer. When your battery gets low, you will see the first low battery warning dialog on the screen. Continue to use your iBook or PowerBook G4 computer until it goes to sleep. At that point the battery has been sufficiently drained for calibration.

3. Connect the power adapter and leave it connected until the battery is fully charged again.


Note: You have to fully charge and then discharge your battery only once to calibrate it. After that, you can connect and disconnect the power adapter when the battery is at any charge level.

Important: When the battery reaches "empty", the computer is forced into sleep mode. The battery actually keeps back a reserve beyond "empty", to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced into shutdown. At this point, any open files could be lost. Therefore, it is important that you find an electrical outlet and connect the adapter before the forced shutdown occurs.

[Edited on 5-10-2004 by Adel]

[Jumbo]

Marketing tlga... hay... mine reads 4 hours max.. i guess i shuld be happy about that.

Just curious Adel, the manual said you should calibrate it only once. so will there be damage if we calibrate it in a couple of months as you said?

[Adel]

Originally posted by Jumbo
Marketing tlga... hay... mine reads 4 hours max.. i guess i shuld be happy about that.

Just curious Adel, the manual said you should calibrate it only once. so will there be damage if we calibrate it in a couple of months as you said?

No. I didn't say it, Apple did. Read the quote from the Apple Knowledge Base document in my post more carefully:

The battery needs to be recalibrated from time to time to keep the onscreen battery time and percent display accurate. You should perform this procedure when you first use your computer and then every couple of months thereafter.

[Jumbo]

Ah ok sorry hehe :blush:

[maryannemoll]

thanks adel! iguess i did it right a couple of days ago then. now i know why you guys have extra batteries.

[Melancholy]

Hi,
I haven't changed my ibook battery since I bought it coz it's always plugged when I use it. Though recently I tried watching DVD and it went to sleep in about 5 mins time. Anyway, how does one know if the seller is giving me an old version/unit even if it's in a box?
Thanks in advance.

[Henjie]

Originally posted by Melancholy
Anyway, how does one know if the seller is giving me an old version/unit even if it's in a box?

I think the only sure way to know is to ask for a sealed box.


~Henjie