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zRedbullz
Nov 28, 2010, 06:24 AM
Hello,

According to Coconut battery, my MBA is 9 weeks old and the capacity has dropped to 96%.

Is it normal?

I didn't quite expect it to drop 4% in just a matter of weeks.... I did one battery calibration when I bought it since new.

Thank you



SandboxGeneral
Nov 28, 2010, 06:27 AM
Yes it is very normal. Check out this thread: Apple Notebook Battery FAQ (http://forums.macrumors.com/showpost.php?p=9875442&postcount=23)

jimboutilier
Nov 28, 2010, 10:34 AM
Mine came wit a 0 cycle battery at 98% health which did not make me particularly happy but after a few cycles it registered 99%.

One thing for sure is that every battery will deteriorate with use, cycles, and time. It's just a matter of how fast.

My uMB is at 100% still after over two years of use but I've had others deteriorate much faster. Usually I get several years before health reduced battery life to the point I'd consider replacing the battery.

Not sure of the cost of a new MBA battery will be but Apple would replace the old ones for about $100. And if the age of the battery or number of cycles on it was within apples spec when the battery reported It needed replacing, the replacement is a free warranty item.

MonkeyET
Dec 1, 2010, 10:30 PM
I just decided to try out coconut battery on my 4 month old MBP. It shows I have only 88% of capacity (5125 mAh of 5770 mAh). I have only ran 17 battery load cycles. Does this seem normal? I have tried googling, searching forums, and many seem to have it be 95% for the first 30+ cycles so this seemed odd.

GGJstudios
Dec 1, 2010, 10:47 PM
I just decided to try out coconut battery on my 4 month old MBP. It shows I have only 88% of capacity (5125 mAh of 5770 mAh). I have only ran 17 battery load cycles. Does this seem normal? I have tried googling, searching forums, and many seem to have it be 95% for the first 30+ cycles so this seemed odd.
Have you properly calibrated your battery? See the link in post #2 for the calibration procedure. How often do you run your MBP on battery power, and how much on AC power?

MonkeyET
Dec 1, 2010, 10:55 PM
I almost always run on battery. I guess I thought it was bad to keep it plugged in but from what I have read, I was wrong. I have not calibrated but am in the process of charging it to max value as we speak.

GGJstudios
Dec 1, 2010, 11:01 PM
I almost always run on battery. I guess I thought it was bad to keep it plugged in but from what I have read, I was wrong. I have not calibrated but am in the process of charging it to max value as we speak.

If you read the information in that link, you'll find how best to use your battery to maximize its life.

darknite38
Dec 1, 2010, 11:30 PM
My 13" 2009 MBP is at 139 charges, it fluctuates between 95 and 97 most of the time - Never seen it go 94% or lower.

chrono1081
Dec 2, 2010, 02:04 AM
FYI Apps like Coconut Battery are estimations only. You will see a TON of misinformation (I've seen it on these forums) where people who don't know what they are talking about say things like "Coconut Battery is accurate because it reads the battery straight from the system!!!11!" Yes, it does, and the system only provides an estimate, nothing more.

Anyway its perfectly normal and you usually will never see 100%.

efirmage
Dec 2, 2010, 12:01 PM
Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8B117 Safari/6531.22.7)

Yeahi have gone through 9 cycles and am at 96%. Worried me a bit, and will probably keep the power in more for normal use.

BeyondtheTech
Dec 2, 2010, 12:37 PM
I've gone through five different MacBooks and Airs over the past three years, and I've always seen my batteries stop anywhere from 96% to 100% each and had as many as 400 cycles, so I wouldn't be worried. I think it's just a calibration issue.

GGJstudios
Dec 2, 2010, 12:40 PM
Yeahi have gone through 9 cycles and am at 96%. Worried me a bit, and will probably keep the power in more for normal use.
Read the AC Power section of the Apple Notebook Battery FAQ (http://forums.macrumors.com/showpost.php?p=9875442&postcount=23) for recommended battery/AC usage.

gwsat
Dec 2, 2010, 01:42 PM
FYI Apps like Coconut Battery are estimations only. You will see a TON of misinformation (I've seen it on these forums) where people who don't know what they are talking about say things like "Coconut Battery is accurate because it reads the battery straight from the system!!!11!" Yes, it does, and the system only provides an estimate, nothing more.

Anyway its perfectly normal and you usually will never see 100%.
That's right. Apple's battery FAQ has this to say on the matter:

Your battery health is referred to either as a percentage or in mah and represents your current full charge capacity (mAh) as compared with the ideal full charge capacity (100%). Be aware that battery readings are not 100% accurate and they fluctuate up and down, so if your brand new battery health is somewhat less than 100% or if it fluctuates up and down over time (100%, 91%, 95%, etc.), don't worry. It will not only decline. For example, if your battery health is 92% one day, it could be back up to 97% a few days or weeks later. It is not a one-way fluctuation. This is completely normal.

MonkeyET
Dec 18, 2010, 04:10 PM
I guess I was premature on my post. I had always run it off of the battery instead of using the plug when I was nearby. In the last two weeks I have since changed these behaviors and Coconut Battery now shows 93% capacity. I suppose you learn as you live.