I have a 15" MacBook Pro 3.1 (that is Late 2007 model AFAIR). I've bought it new a couple of years ago.

Recently its on-battery power lifespan became very short (30 to 10 minutes).

When my notebook turns itself off due to "low battery" and I press the small button on the battery itself, all LED lights are alight, indicating full charge.

When I plug in the power adapter, my Mac displays that "battery is fully charged, finishing charging process" (I have a Russian OS X 10.5.7, so that is a rough translation), but the LEDs on battery itself display (seemingly accurate) status that there are one or two "LEDs still not charged".

My battery have as few as 37 recharge cycles (yes, I've neglected calibration over the time I've used it). Battery info programs like iBatt2 report battery capacity of 65 337 mAh (with by-design capacity of 5600 mAh).

I get it that something went wrong with battery electronics.

I've tried resetting my Mac's PRAM and SMC, it did not changed anything.

Now I'm trying to recalibrate the battery, but looks like it does not help as well. Will try to recalibrate it several times in a row.

I'd buy a new battery if I knew if it is battery fault, not a notebook's.

Any suggestions?


After recalibration, my battery status now displays battery capacity of 1500 mAh. But with every recalibration (or simply when I use notebook without power adapter plugged in) this number changes in the range from 200 mAh to 1700 mAh.

LEDs on battery now are synchronous with what nodebook thinks on the charge level.

Also I've noticed that cycle count changes rather slowly. It is now 39, it was 37 when I've started recalibration, and I went through the process at least ten times...

So, the main question is: does it look like that replacing the battery would help me (or does it look like this is notebook's problem)? I guess I should try replacing the battery.

  • 1
    As far as I know, calibration really only tells the chip on the battery how well it performs. Calibrating a Mac battery will not extend its lifetime, I think. See also apple.com/batteries and "Is it better to use laptop on battery or on AC power?" at superuser.com/questions/12358/… – Arjan Jul 25 '09 at 10:52
  • 1
    Well, yes, but that 65K mAh indication looks pretty much like a chip issue... I'm not a battery expert in any way of course. :-) – Alexander Gladysh Jul 25 '09 at 11:57
  • No answer to your question, but the charge cycle count is explained on above-mentioned apple.com/batteries -- but I agree that doing 10 calibrations should add 10 cycles then... Just curious: what do the LEDs on the battery indicate now that you've calibrated? – Arjan Jul 30 '09 at 10:46
  • Now it seems that LEDs do match what notebook thinks on the charge level. – Alexander Gladysh Aug 1 '09 at 20:17

Battery issues are not much related to NVRAM/PRAM, but to the SMC. See Apple Portables: Resetting the System Management Controller (SMC).

If this is the first time you calibrated your battery: after I purchased a new battery, my Mac would shutdown suddenly when the battery was running low, even after calibration. For some reason, it took me a few calibrations to fix that. I can't explain why, and it's quite likely that something else fixed it, but in the end the chip on the battery finally learned the true capacity of the battery. So, maybe one or two more calibrations might help...

  • I did reset SMC as well (by disconnecting adapter, removing battery and holding Power button for 5 seconds). I've noticed no changes. :-( Trying to calibrate once more... – Alexander Gladysh Jul 25 '09 at 10:42

I had the same problem on my 2006 MacBook pro and it turned out that some batteries manufactured around 2006/2007 were simply broken by production.

IIRC, at that time Apple had published an official announcement to replace batteries without cost for computers that qualified for the change. I checked the website and found out that my battery qualified for a change but my computer did not :-(.

Nevertheless, after replacing the battery by a new one everything works just fine.

  • They replaced my late 2006 MacBook Pro battery when it went kaput and the new one is totally dead a few years later: 0 mAh == unplug for 1 second and it goes into deep sleep (if I'm lucky and it doesn't shut down all the way). – Jared Updike Oct 22 '09 at 19:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.