07-02-2010, 03:05 PM

Hey! The green light on the charger for my new MBP (about two and a half weeks old) has been on since last night, but the icon at the top is saying that the battery is only 96% charged. Why is this?

EDIT: I restarted it and it's not charging. I would still like to know why this happened, though. Thank you!

07-02-2010, 04:28 PM

Have you done a battery calibration yet? Mac OS X 10.6 Help: Calibrating a portable computer battery

Also here is some more information about notebook batteries: Apple - Batteries - Notebooks

07-02-2010, 06:28 PM

If the power cable is unplugged once the machine reaches 94 or 96% (I forget which) and then plugged back in, it will not charge the machine any further until it goes below that percentage.

Also, once the machine is charged up to 100% with the power cable - the machine does use the battery to some extent even while the cable is plugged in. As it is used the percentage will drop and it will still not charge the battery until it goes below the above percentage.

12-20-2010, 06:39 PM

when the mbp reaches 100 percent, I believe the charger stops feeding the battery and runs from only the ac adapter. I say this because whenever my battery reaches 100 percent, the light indicator stays green and charge stays at 100 percent even after hours of use. So im not sure if thats true that it still uses battery after 100 percent

12-20-2010, 07:04 PM

If the charger would keep giving the battery power even when its full the battery would be damaged. The charger senses when the battery is full and stops charging the battery. When the charge in the battery goes down to around 95 - 96% the charger will start to charge the battery again until it reaches 100%. It does this cycle all the time. Nothing to be afraid if, its normal.