[Bandit240]

How low does the battery have to be before it starts to charge the battery? Right now its at 97%, plugged in, but not charging. Last night it stayed plugged in all night, but stayed at 94%. On our iBook it will charge no matter what % it is at. This isnt really an issue, but its bugging me.

[Kyle Dreaden]

It's strange, I've noticed the same thing with my 12" PB. I barely use it on AC power considering I have a lovely Powermac + ACD for that, so when I'm at home or asleep, my PB is always plugged in and asleep.

I'll be on location or at work with the 'book and the battery will get down to something around 70-80%. The next morning, after a good six or seven hour charge, it'll only be at around 95%. It doesn't really bother me all that much considering I'm not doing any real heavy lifting on it, but I found the behavior rather curious.

Mind you, my PB was a display unit from the Apple store (Anyone remember the library "all the books you'll ever need" promo window during back to school?), so the battery had some wear on its life I'm sure.

[rag on a muffin]

Originally Posted by Kyle Dreaden

It's strange, I've noticed the same thing with my 12" PB. I barely use it on AC power considering I have a lovely Powermac + ACD for that, so when I'm at home or asleep, my PB is always plugged in and asleep.

I'll be on location or at work with the 'book and the battery will get down to something around 70-80%. The next morning, after a good six or seven hour charge, it'll only be at around 95%. It doesn't really bother me all that much considering I'm not doing any real heavy lifting on it, but I found the behavior rather curious.

Mind you, my PB was a display unit from the Apple store (Anyone remember the library "all the books you'll ever need" promo window during back to school?), so the battery had some wear on its life I'm sure.

Ive been having the same problem but much worse. from 30% to 100% in a month.

[Bandit240]

It seems that this is just a werid issue. I took mine to my sisters and ran the battery down to around 50%. When i got home i plugged it in wile it was sleeping and it the light went amber to say it was charging, 10 minutes later when i opened it up the light went green. After about 5 minutes of useing it, the light went back to amber and the system profiler said it was charging. Up 87% right now and still charging.

[bookofjames]

Seems to me that either the batteries are dying or you need to recallibrate ur batteries.

[ibook_steve]

The battery will rarely, if ever, get up to 100%. It usually gets to about 95% to 99% and then stop charging.

Steve

[psk-ele]

With the Li-Ion batteries in the powerbooks, they usually charge to 100%, then stop charging until they reach anywhere from 95-98%, at which point they start charging again. This is a way for the batteries to maintain a longer life, overcharging would severely degrade the life of your battery (ie-always at 100% charge). Li-Ion batteries also do not handle being discharged completely repeatedly very well. You used to have to do that with Ni-Cd batteries due to memory effects, but those are nearly non existent with the Li-Ion.

Even though these powerbook batteries are really great, after awhile they will start to degrade on their own as the powercells start to wear out, either from excessive charging/recharging, or just with age (hey, they don't last forever). Mine is not quite two years old, and it will only charge to about half of its capacity. If you want to get a whole lot of random statistics about yoru battery, use the program coconutbattery. It is free and allows you to see exactly what your battery will hold in charge vs. what the orignal charge carrying capacity was. Useful if you suspect your battery is dying.

Also, if you ever buy a new battery for your Powerbook, most of the third-party batteries do not contain the essential circuitry to back-up your data prior to a shut-down (in the event the battery reaches 0% charge) it will be just like cutting the switch. Apple's sense when the battery is near empty and quickly save the data you are currently working on and put the laptop to sleep (like shutting the lid on your powerbook). Since my battery is so weak, it normally just saves the data and shuts off, but when it was newer I used to get the pulsing white light.

Another way to preserve your battery is to actually take it out of the powerbook if you will be using your powerbook primarily as a desktop replacement. I know this sorta leaves it wobbly, but, that may work for you ( I just leave mine in).

But I would follow bookofjames' advice and calibrate the battery a couple of times a year. That means running it down to 0%, then charging it up.

[Jawbone54]

Definitely calibrate the battery. They don't constantly remind you to do it without good reason.