Battery health?

rayjay86

macrumors 6502
Original poster
May 15, 2011
279
17
Hey guys quick question:

I bought my 2011 MBA shortly after they were released, I think I got it around November.

Since then I've used my MBA entirely for school, taking it with me daily and usually using it constantly, bringing it home with a charge usually in the range of 30-40%. On occasion it dips down below that and once or twice it has gone to the "reserve power" warning.

My battery health (iStat Pro and Coconut Battery) show that I'm at 90% with 235 cycles. My understanding was that Apple ensures 1000 cycles before 80% health and that past 300 cycles the battery isn't covered under applecare anymore? Is that correct?

Why is my health so low then? At this rate I'll reach 80% before 500 cycles...



Side note: anyone know how I can get a copy of my receipt of purchase for my mba? I bought it in store and had the paper receipt when it was shipped to me but I've since lost it (moved twice since then).
 

GGJstudios

macrumors Westmere
May 16, 2008
44,427
762
My battery health (iStat Pro and Coconut Battery) show that I'm at 90% with 235 cycles. My understanding was that Apple ensures 1000 cycles before 80% health and that past 300 cycles the battery isn't covered under applecare anymore? Is that correct?
It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. For further details, read the CHECKING STATUS AND HEALTH section of the following link.

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

rayjay86

macrumors 6502
Original poster
May 15, 2011
279
17
Thanks for that, it was very helpful.

Any idea on how I can get my receipt from when I purchased it? Or even an invoice order? I tried logging into Apple and searching for it but it only seems to have a record of my online orders. I bought my MBA in-store.
 

sarah11918

macrumors member
Aug 14, 2010
97
5
Canada
Interesting. That page does say:

The built-in battery of your MacBook, MacBook Pro or MacBook Air is designed to deliver up to 1000 full charge and discharge cycles before it reaches 80 percent of its original capacity.
My 2010 MBA battery is at 568 cycles and has been showing 75 - 79% capacity over the past couple of days I've been checking. I know they said that the number doesn't always go down (it was first at 75%, and just now 79%), so I wonder if that's within the acceptable margin of error. It's only half the cycles they claim, and under 80% original capacity.

This quote is on the MR FAQ page, but I don't see it on the original Apple page:
If you have a battery that has failed to meet its expected lifespan, assuming your battery is properly calibrated (for those models that need calibration), you may have a defective battery. If so, contact AppleCare to see if they will replace it.
I guess it can't hurt for me to contact them, eh? But I wonder if they don't "guarantee" those results (anymore?).
 

GGJstudios

macrumors Westmere
May 16, 2008
44,427
762
My 2010 MBA battery is at 568 cycles and has been showing 75 - 79% capacity over the past couple of days I've been checking. I know they said that the number doesn't always go down (it was first at 75%, and just now 79%), so I wonder if that's within the acceptable margin of error. It's only half the cycles they claim, and under 80% original capacity.
If you have AppleCare coverage, take it to Apple. They will likely replace it free.
 

Hexiii

macrumors 65816
Jun 30, 2011
1,113
373
Prague, Czech Republic
Why is it good to make full cycles if it reduces the battery health? Because I have it almost always plugged in, few cycles and the battery health is on 97%.

Or is it just about that that when you do the cycles the battery will last longer for shorter time? If it's not confusing lol.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,427
762
Why is it good to make full cycles if it reduces the battery health? Because I have it almost always plugged in, few cycles and the battery health is on 97%.
What do you mean by "full cycles"? Read WHAT IS A CYCLE? in the FAQ I posted.

Also read AC POWER in that FAQ, where it states that leaving your MBA plugged in all the time is bad for your battery's lifespan. Batteries need to be used periodically to stay healthy
 

sarah11918

macrumors member
Aug 14, 2010
97
5
Canada
Just to update, my battery said 73% this morning (the lowest yet) and the "Condition" in the "About this Mac" section now reads "Service Battery."

(I can't be sure when the condition changed from "Normal" since I was using Coconut Battery all week to check my stats.) So to the OP, I guess the good news is that if your battery health really does decline a lot, like mine did, the status on the machine should change and with Apple Care, I don't see how they can't do something about it.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,427
762
Just to update, my battery said 73% this morning (the lowest yet) and the "Condition" in the "About this Mac" section now reads "Service Battery."

(I can't be sure when the condition changed from "Normal" since I was using Coconut Battery all week to check my stats.)
The "Service Battery" indicator usually comes on when the battery health drops below 75%.
 

tim100

macrumors 65816
May 25, 2009
1,368
0
What do you mean by "full cycles"? Read WHAT IS A CYCLE? in the FAQ I posted.

Also read AC POWER in that FAQ, where it states that leaving your MBA plugged in all the time is bad for your battery's lifespan. Batteries need to be used periodically to stay healthy
what does "used periodically" mean?

also what is the capacity of the 13 mba? coconut lists designed capacity of 6700. i have never personally seen one over 6400.
 

mattopotamus

macrumors G5
Jun 12, 2012
13,339
3,524
i have always used my laptops until the battery either runs out or is in red. I sold my 2011 macbook pro a few months ago with over 200 cycles on it and 100% health doing this.
 

mattpreston11

macrumors 6502a
Nov 9, 2007
731
0
For reference my 2010 MBA had around 235 cycles and 92% health.

I wouldn't get too upset by these things.Unless you plan on keeping a laptop for many many many years.

Kind of like driving a brand new car "enthusiastically" and selling it 3 years on.
 

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