New MBP - Battery health question

[gtgrad95]

My MBP is only 2 days old. I noticed right away using iStat that the battery health was 94%. I found that a little odd for a brand new battery. I thought calibrating would probably fix this. I completely drained the battery until it went to sleep. I then charged to the full 100% and left the A/C adapter plugged in, as per the calibration steps on the Apple website. I then noticed that the battery health is now 93%. The charge cycle count is 4.

Do I have a defective battery that needs to be replaced? Shouldn't the health be 100% or very close to it?

 

[gtgrad95]

Here are the stats from coconutBattery:

Current Battery Capacity: 5166 mAh
Original Battery Capacity: 5500 mAh

Battery Loadcycles: 4
Age of your Mac: 5 weeks

The laptop is only 2 days old and the build week was 26. The current week is week 28. How can it be 5 weeks old??

 

[RichL]

If memory serves me correct you must drain batter until sleep and then let it sit for 5 hours or so. Did you do that/can anyone confirm?

 

[gtgrad95]

If memory serves me correct you must drain batter until sleep and then let it sit for 5 hours or so. Did you do that/can anyone confirm?

Yes, I let it go to sleep and kept it in that state overnight and most of the next day.

 

[beginner0]

I made a thread about this a few days ago. 2 days after I got my MBP the health was 96%. I doubt they would replace just for a few percents though.

 

[iBookG4user]

Do I have a defective battery that needs to be replaced? Shouldn't the health be 100% or very close to it?

Yes, it should be about 99% or around there. You should at least call and ask Apple if you could get a new battery.

 

[Zwhaler]

When I bought this MBP the battery was at 98 and later went to 97. I calibrated and it went to 100. Now it is telling me it is at 98 and keeps going back and forth between 98 and 97. Will it continue to deteriorate? (I calibrated last night, the 98 reading is after calibration)

 

[iBookG4user]

When I bought this MBP the battery was at 98 and later went to 97. I calibrated and it went to 100. Now it is telling me it is at 98 and keeps going back and forth between 98 and 97. Will it continue to deteriorate? (I calibrated last night, the 98 reading is after calibration)

Yes, all batteries lose capacity over time. But if it's at 98% then there is nothing wrong with it.

 

[KristieMac]

Mine's at 23 cycles, 97% health. I've calibrated it twice since I've had it, which is about a month.

As far as I know, the nature of these batteries is to slowly deteriorate as they are used.

 

[Mechcozmo]

The laptop is only 2 days old and the build week was 26. The current week is week 28. How can it be 5 weeks old??

Shipping time. When your Mac was built and all, that's when you start counting. Also, coconutBattery may be guessing wrong-- plus or minus two weeks.

Yes, I let it go to sleep and kept it in that state overnight and most of the next day.

To elaborate: Once the computer goes into it's emergency-sleep mode, you need to wait until the battery is finished draining. This is for Safe Sleep computers only. Read this: Linkety to kbase article.

AppleCare will replace the battery when it drop below half the rated capacity within the warranty period. (If memory serves me correctly)

 

[hsotnicaM]

Mine showed the same thing four days after starting up the first time. I noticed I had plugged in the AC adapter about 96% and it stayed there. The next day I drained it to 50% then plugged in the adapter to charge. It then charged to 100%. it is my understanding the battery is set up not to over charge, so if it isn't drained below 90% it will not charge.

 

[Mechcozmo]

Mine's at 23 cycles, 97% health. I've calibrated it twice since I've had it, which is about a month.

As far as I know, the nature of these batteries is to slowly deteriorate as they are used.

And even when they are not used. LiIon batteries start the process of dying as soon as they're built.

I'm at 515 loadcycles in 38 months. The battery may stabilize in the 90s or so... mine did.