A few days ago (8/12), I decided I needed to calibrate my battery, since I hadn't done so since June 11. At that point, it was registering 91% of original capacity (coconutBattery). Well, while I was using it, it suddenly went from 22% to 0% instantly, and the capacity fell to 85%.
Later, when I went to charge it, it didn't charge properly...it went up to 75-80% (not sure exactly what), and then suddenly started charging very slowly. The current readout from CB would go up by only 1mAh every time it updated, and the "time until full" thing in the OS X battery menu gradually increased. Around 82%, it jumped to 100% out of nowhere and was declared full.
This bugged me, of course, so the next day I calibrated it again. (It spent the night plugged in on sleep.) This time, it fell from the same 22% to 0%, and reported 79% charge - another six percentage points! Same charging problem. Later that day I did the same thing yet again, and it only went from 14% to 0% this time - an improvement. But the battery still wasn't charging right, and capacity was down to 73% (down six again).
I didn't do anything yesterday, all just plugged in...so today, I did it once more. This last time, it got down to 6% before reporting 0%, the capacity in CB is listed at 70% (down less), and it appears to be charging properly - it's currently at 92% and going fine.
Sorry about going on so long....but, what is going on here? Is it because I went so long between calibrations? Is it just a crappy battery? I mean, I only have 116 cycles on it. I've reset the PMU and NVRAM, and have tried taking the battery out and putting it back in (with the machine turned on).
Below is a screenshot of coconutBattery illustrating all this.
Top