OSX shows battery at 100%, Bootcamp at 96% .. What?!?!

entraik

Suspended
Original poster
Jan 22, 2009
602
208
Okay so i'm in OSX now, and battery is 100% charged while the charger is in. I switch over to bootcamp and it's at 96% (plugged in, not charging??). Why am I getting different battery readouts and why is it only charging up to 96% in bootcamp and not 100%?
 

GGJstudios

macrumors Westmere
May 16, 2008
44,419
756
Okay so i'm in OSX now, and battery is 100% charged while the charger is in. I switch over to bootcamp and it's at 96% (plugged in, not charging??). Why am I getting different battery readouts and why is it only charging up to 96% in bootcamp and not 100%?
Battery readings are only estimates and not 100% accurate. I wouldn't worry about it.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,419
756
Are you using a Retina MacBook Pro because I've seen issues similar to that using iStat Pro on my dashboard?
That's been discussed in a few threads. There appears to be a slight discrepancy (roughly 5% difference) between 3rd party apps and ML in reporting battery charge percentage. I expect future updates to iStat Pro and other apps will correct this.
 

Idefix

macrumors 6502a
Jul 10, 2012
523
72
http://support.apple.com/kb/TS1909

Quote:

Note: PowerPC-based computers may stop charging between 95 and 99 percent; Intel-based computers may stop charging between 93 and 99 percent.

Resolution

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.

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 93 or 95 percent and 99 percent.

The adapter will not charge the battery to 100% automatically if it will add additional wear to the battery.