Battery Heath Dropped 10% After Calibration

[tardman91]

Last night I calibrated my battery. Let it fully charge for 2hrs, took it off the charger, turned up the screen brightness and keyboard backlight all the way, then proceeded to run the battery down watching videos and whatnot. It went to sleep and I went to bed to let it sit for 5 or more hours. Woke up, charged it up, turned it on and noticed that I went from 97% to 87% (coconut battery says 86%) and I only have 54 cycles. Should I go to the genius bar or something? Or try re-calibrating the battery? Did I do something wrong when I did it? Does it matter how long it takes to run down the battery after it's fully charged? I'm kind of pissed I lost 10% overnight. Seems to me that something isn't right. On, and it's a 2009 model. I bought it in November. 2.26 ghz with 4mb of RAM.

 

[GGJstudios]

This should answer most, if not all, of your battery questions: Apple Notebook Battery FAQ

 

[tardman91]

Would my situation be considered a manufacture defect since the apple website says this "The built-in battery in the new 13-, 15-, and 17-inch MacBook Pro is designed to retain up to 80% of its original capacity at up to 1000 full charge and discharge cycles."

And on a side note I just checked iStat Pro and my health just went up to 91%. Odd.

 

[GGJstudios]

So if my % drops below 80% before I reach 1000 cycles (at the rate I'm going I should be there before I even reach 100) then would they replace my battery?

Generally speaking, probably, since that would likely indicate the battery is defective, unless you've abused it by leaving it plugged in 24/7.

 

[alust2013]

It fluctuates quite a bit, like mine has been anywhere between 98 and 93% within a month. I wouldn't worry about it unless it drops significantly again.

 

[tardman91]

So I guess I'll wait until it drops below 80%, then bring it in and see about getting it replaced. Guess I better get me some Applecare. I have until November to decide.

 

[tardman91]

Generally speaking, probably, since that would likely indicate the battery is defective, unless you've abused it by leaving it plugged in 24/7.

I charge it every night, but most evenings I run it down off the charger sitting on the couch.

 

[NovemberWhiskey]

From my experience, your battery health improves if you drain it slowly when calibrating (i.e. turn off the screen, and just let it idle [turn off sleep]).

 

[rk1991]

From my experience, your battery health improves if you drain it slowly when calibrating (i.e. turn off the screen, and just let it idle [turn off sleep]).

I am going to try that in the next day or two. I had the same experience as the op. My health was 97% according to coconut battery but suddenly dropped down to 86% after calibration and I only have 77 cycles. And since you mentioned it the last calibration I did, I kept the brightness full, volume full and played music the entire time while mail, firefox and caffeine were running.

 

[diablo2112]

My best advice is to completely ignore all these stats on the MBPs. Battery capacity, temperature, fan speed, etc. Frankly, folks pay WAY too much attention to this stuff. Just use your computer and enjoy it. It's under warranty. If at some point, something doesn't appear right (like, it won't charge, or it only lasts half as long, etc.), then do a bit of poking around or take it in. Until then, you'll likely do more damage to YOURSELF through stress and worry than any gain to be had by prying around the technical specs on the machine.

 

[7thMac]

Calibration does not increase battery life - the purpose is to increase accuracy of the gauge. Hopefully, the complete discharge does not reduce battery life. I think calibration is not worth the time. (No pun intended!) I have my gauge set to only show the bar length and not the percentage / time left. Life is too short to worry about your battery details. It will be obvious when your battery is no longer getting the job done.