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KraziKid · Dec 23, 2003, 12:36 AM

Something weird happens when my PowerBook is plugged in and the battery is left in it's bay. After the battery is fully charged, and it is running on AC, the battery starts losing charge. For instance, it will fully charge and be at 99% (I understand that is normal). Over time, the percentage will actually start to go down. The meter will start to read 98, 97, 96, etc... while still saying fully charged. Has anyone else seen this?

desertmac · Dec 23, 2003, 12:45 AM

Yes, though mine is a little different. Have a 15" 1.25. I have two batteries, and they both exhibit the same behavior. They charge fully to 100%, and then after awhile, they show a charge of 99% (usually), or 98% (sometimes). They haven't ever gone below 98%.

What's more interesting is that I have had 3 al powerbooks (white spot returns), and all of the batteries exhibited this behavior as soon as I installed any version of Panther. I never saw this under 10.2.8.

Orion27 · Dec 23, 2003, 07:05 AM

From my understanding the Powerbook allows the battery to be charged to 100%. While continuing to run on the powersupply, the battery will not be maintained at 100%. Instead, it is allowed to trickle down, normal loss of voltage over time, to a point of 95% of full charge, at his point the charger tops off the battery to 100%. Makes sense since a constant trickle to keep battery at 100% over time would be damaging.

desertmac · Dec 23, 2003, 12:31 PM

Ahh, it's a FEATURE!

Thanks Orion27. That does make sense. I appreciate the clarification.

bkb · Dec 23, 2003, 08:35 PM

Originally posted by desertmac:
Ahh, it's a FEATURE!

Thanks Orion27. That does make sense. I appreciate the clarification.

I remember this being discussed back in October, when the Rev Bs were just arriving. My Rev B charge has trickled down to 96%. I haven't discharged it in a month or so. Started at 100%. The next day it was around 99% - and then very gradually it has reached 96%.

The reason - I am told - is because earlier batteries would continuously be charging/discharging in the 95%-100% range. This apparently damages the battery. So Mac has prevented the Rev B batteries from charging if they are <100% but >95% range.

I don't know if the new Battery Update addresses this. I haven't installed it yet. I'm waiting to hear feedback first.

Thanks,
BKB.

KraziKid · Dec 30, 2003, 07:26 PM

Originally posted by bkb:
I remember this being discussed back in October, when the Rev Bs were just arriving. My Rev B charge has trickled down to 96%. I haven't discharged it in a month or so. Started at 100%. The next day it was around 99% - and then very gradually it has reached 96%.

The reason - I am told - is because earlier batteries would continuously be charging/discharging in the 95%-100% range. This apparently damages the battery. So Mac has prevented the Rev B batteries from charging if they are <100% but >95% range.

I don't know if the new Battery Update addresses this. I haven't installed it yet. I'm waiting to hear feedback first.

Thanks,
BKB.

What you said made complete sense until now. I have had my PowerBook plugged in for a while now (more than a few days), and I just glanced at the battery meter. It now says 94% while, and the green light is on (so it is not charging). Has anyone else who has the powerbook plugged in a lot seen this? I am running 10.3.2 and the battery update.

Orion27 · Dec 30, 2003, 07:46 PM

yeah I don't think it's problem. Truthfully, you deal with thhe hand your given. If you are going to need the book and max battery duration, unplug and replug the power supply and bring it up to 100%. Otherwise, just consider the the lost 6% as the cost of doing business. If you have to have 100% on the fly, get another battery and charger. How many things in life are 100% ? So if you thinking perfection, forget it.

filmerp · Dec 30, 2003, 08:42 PM

So what's the conclusion of this 'feature'? Is the battery meant to be left in the PB after it's fully charged and plugged in? Or does the battery sustain any damage as a result of constantly being charged/discharged in the 94-99% range?

KraziKid · Dec 30, 2003, 09:07 PM

Originally posted by filmerp:
So what's the conclusion of this 'feature'? Is the battery meant to be left in the PB after it's fully charged and plugged in? Or does the battery sustain any damage as a result of constantly being charged/discharged in the 94-99% range?

Well, mine wasn't being recharged, it just seemed to lose the charge. So I don't know.