rMBP Battery Indicator Issue

Working as intended it would seem. It reports 100% when it gets to around 97%. Maybe because the last 3% take so long to charge?

I imagine this is either what they wanted, or it will be fixed soon.

 

Hmm, I don't have this issue, but have you drained the battery to zero to "calibrate" the scale of battery level yet? Give that a try.

 

It is because the battery is holding a larger charge than it is designed for so Apple's built in percentage is off of the designed capacity while iStat is what the full charge is.

 

I've actually had this in my old 13" MBP. It's not a big deal and it never became a problem for me. And if it ever does becomes a problem in the future, you know you can always go back to the Apple Store.

Also, I think you're fine with the discrepancy between the iStat and the charge % reading on the OS. I've had this on my 13" MBP, too, though I have yet to test this on my rMBP. I very much doubt there's a problem with the batteries.

In conclusion (ughh, I hate that phrase), I think your rMBP is just fine.

 

There is no need to calibrate these batteries, all you are doing is consuming cycles. The system just needs to be used on the battery every 4-6 weeks to keep the electrons flowing and prevent premature failure, down to 20% is more than enough.

Following the old calibration routine on a new machine only fools you into thinking that you are doing some good, as the battery takes several cycles to reach optimal performance from new.

 

It's nothing to worry about. Battery readings are estimates, and not 100% accurate.

The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries.

That's not true. The battery can't hold a charge more than it's designed for.

This should answer most, if not all, of your battery questions:

Apple Notebook Battery FAQ​

 

Sometimes I unplug my gf's MacBook and she gets pissed. " you just wasted a cycle/charge". I've read a few places that you have so many charges or cycles. Do you know anything about this?

 

If you need to run on battery, do so, but don't cycle a battery simply for the sake of cycling it. Read the BATTERY LIFESPAN section of the Battery FAQ I posted.

 

The more cycles you pile on, the lower the battery capacity gets. It depletes pretty slowly though.