10-07-2005, 10:46 AM

I have noticed in the past several months that for some reason, my computer's battery appears to lose charge even when plugged in, albeit at a slower rate than it would if unplugged.

Example: I charge my iBook to 100%. I continue to use the iBook with the charger plugged in, and very gradually the charge drops down to 94%, at which point the charger kicks in and recharges the battery to 100%. If I recall and understand correctly, the battery is supposed to stay at a full charge while plugged in, right? As I remember, that's how it used to work. It just doesn't now.

Does it sound to you like my charger is messed up? And does Apple have an exchange program for faulty chargers?

10-07-2005, 01:30 PM

Does the light on the iBook stay green or drop back to orange when tbattery is dropping?

10-07-2005, 01:44 PM

Apple Support to the rescue. Read this.

PowerBook G4, iBook battery does not show a full charge in Mac OS X
Some PowerBook G4 and iBook computers may not show the battery as 100 percent charged in Mac OS X, even when the power adapter is plugged in. The battery appears to stop charging between 95 percent and 99 percent.

This is normal. The batteries used in these computers are designed to avoid short discharge/charge cycles in order to prolong the overall life of the battery. Because of this, when setting the Mac OS X battery status menu bar icon to display charge state by percentage, you may notice that the reported charge stays between 95 percent and 99 percent. When the battery level eventually drops below 95 percent, it will charge all the way to 100 percent.

10-07-2005, 02:02 PM

I believe power adapters are considered a consumable, Because they can be broken easily. As for the green/orange light. The light is green when the power adapter is not charging and orange when the power adapter is charging.

As for the 94%, normally if the battery is less than 95%, then your power adapter would start to charge the battery. How old is your system, because power adatper maybe bad as you stated. I am on my third power adapter, since 2001. My wife is still on her first one in that period of time. It appears that I am harder on power adapters, than she is.

10-07-2005, 02:04 PM

After seeing caribiner23 post, you may still have some live left in you power adapter.

10-07-2005, 09:31 PM

That's interesting... I thought that each charge cycle shortened the life of the battery, so I don't get how allowing the battery to go down to 94% and recharging to 100 would extend battery life. Does anyone understand this?

10-07-2005, 09:37 PM

You know, on second reading of the support page, it looks like mine may be a different situation.

Because of this, when setting the Mac OS X battery status menu bar icon to display charge state by percentage, you may notice that the reported charge stays between 95 percent and 99 percent.

I think this is simply describing the fact that the computer is designed in a way that the charger will not charge if the battery happens to be between 95 and 100%. As it says, the reported charge stays between 95 percent and 99 percent. I knew this before. My problem is that my battery doesn't stay charged, as the support page suggests. It loses charge until it reaches 94%, at which point it begins recharging. This doesn't fit the description in that article, and I have to assume it isn't normal, since it was not always a problem.

Has anyone had luck just trading an old charger for a new one straight-up in an Apple store? Should I just break down and buy a new one (as if I have money)?

Thanks for your replies so far.

10-07-2005, 11:03 PM

What the support page is saying is that the computer will allow the battery to discharge down to 95% and then a recharge cycle will kick off. The fact that you are going to 94% is, I think, immaterial.

The reason the computer allows the battery to discharge is because rechargeable batteries work best when they're being cycled. Yes, you do lose a tiny bit of capacity with each cycle, but you can't expect to keep your battery charged at 100% for an indefinite amount of time until you go to use it, say, a year down the road. Batteries, even rechargeables, are consumable items.

(There are lots of other threads on these forums about this, so you may want to do a search. I handled PC support for many years at a couple different companies and I've seen batteries that were never taken off their chargers, in some cases for up to 2 years, and have zero capacity when the power was removed. Every PC manufacturer will tell you to cycle your batteries if you want them to keep running.)

If your battery makes it to a 100% charge, you won't be able to make the argument that there's a problem with your charger. Either it supplies the required voltage or it doesn't. If your battery won't take a charge or hold one, then you have a problem with your battery.

Based on what you've described, it sounds like everything is working normally.

If you are still under warranty, you can call Apple (or better yet, speak to a Genius at an Apple Store) and see what they will do.