battery from 99% to 98%

[mac*]

i just found my battery went from 99% to 98%.
However, when i was using the laptop, it is using AC adapter, with a battry that has been fully charge(why it just goes to 99%, nenver show 100%).
how come the battery will reduce from 99 to 98, even i am useing the AC not the battery?

 

[technologist]

A physical property called "internal resistance," for one.

This happens to all batteries when they're not used. Leave a battery on a shelf or in a kitchen drawer long enough, and it'll lose power and eventually go dead. Rechargeables do this more quickly than, say, a pack of AAs, though. Being kept in a toasty warm iBook bay doesn't help any, either.

When the battery hits 95% charge, the iBook will automatically charge it back to full again. (Recharging over every little percentage point would wear the battery out more.) If you find that your battery never, ever reaches 100%, though, you might want to calibrate. More info at
http://www.apple.com/batteries/notebooks.html
and http://docs.info.apple.com/article.html?artnum=86284

 

[MoltenLava]

Used batteries last longer than unused batteries. It may sound funny, but that's the way it is. Use the battery. When I use my laptop, I leave it unplugged. I plug it in only when I'm done using and walk away, or if the battery is depleted. The dead laptop batteries that you see on old laptop is not due to heavy use, it's due to the lack of use!

 

[TylerMoney]

once you've used your computer for a few months or so...it will never get to 100%

Lithion Ion batteries are that way...and there are several theories on slowing the process...

Some say let the battery completely die everyone in a while.

others say never let it completely die...charge it in shorter sperts...

Some suggest that when you're plugged in to your ac adaptor to take the battery out...

its really an undiscovered world. chose your way to do it...Lithon Ion probably won't last more than two years...unless you're lucky.....and they probably will start getting shoty well before the 2 year marker...like a little over a year maybe...computer technology is ahead of battery technology..but they're getting better everyday.