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JoshuaZ · Aug 12, 2008, 12:14 PM

I've got a Macbook Pro thats turning one years old this month. For some reason my battery Health is at 50%! 2844 mAh and 21 cycles! The System Profiler says that I should "Check Battery".

Just wondering what advice you could throw my way. Thanks.

richwig83 · Aug 12, 2008, 01:06 PM

Try re-calibrating it!!

http://docs.info.apple.com/article.h...en/mh2339.html

wrambro · Aug 12, 2008, 02:03 PM

I'd say it's a bad battery (assuming calibration doesn't help). I had the same situation with mine (which is still under AppleCare) and got the battery replaced for free. And it too, was about a year old.

JoshuaZ · Aug 12, 2008, 07:43 PM

Thank both of you. I'm rather sure its a bad battery. Shortly after I posted the first message my battery died on me. As in my computer said it had %50 power remaining but ran out of juice.

I have AppleCare and will give them a call. (Just annoying as I'm leaving on a long trip tomorrow and taking my laptop with me. Oh well my SuperDrive is near death as well and should be looked at.)

mduell · Aug 12, 2008, 09:51 PM

Sounds normal to me.
Secondary lithium-ion batteries stored at ~100% charge for a year at ~100F (typical temperature inside a laptop) are expected to lose about 35% of their original capacity. Throw in a few abusive cycles and some bad luck and 50% loss after a year is easily achievable.

JoshuaZ · 12:30 AM

Originally Posted by mduell

Sounds normal to me.
Secondary lithium-ion batteries stored at ~100% charge for a year at ~100F (typical temperature inside a laptop) are expected to lose about 35% of their original capacity. Throw in a few abusive cycles and some bad luck and 50% loss after a year is easily achievable.

Hmmm.... yeah... I could see that.

Any reason why my computer would lose power even though the power status says it still has a 50% charge?

UPDATE: So I was going to re-calibrate it and once again the computer abruptly shuts off at around 40% power remaining. No warning. Just off. I looked at my little system stat widget and since yesterday the health of my battery (according to this widget) had dropped from 50% health to 41% health and from 2844 mAp to 2316 mAp. Very strange....

JoshuaZ · Aug 15, 2008, 06:32 AM

So in case anyone cares, or eventually comes across this thread, as of today my health is at 25% and 1439 mAp. So yeah, in about 5 days I've dropped 25% health.

I'm heading into the Apple Store in Milwaukee this morning. Something is up with this battery.

JoshuaZ · Aug 22, 2008, 02:03 PM

I went to the apple store (for the second time) and within 3 minutes I got a new battery. Fun times. Super fun time.

Thanks Apple.

Simon · Aug 23, 2008, 05:36 AM

Good to know it worked out for you.

I have a MB here with 1900 mAh after 170 cycles. I'm going to call Apple and have them send me a replacement next week.

-Q- · Aug 23, 2008, 11:14 AM

I just had to have mine replaced about a month ago for that exact same issue. It would say it has X% left, but would then just up and die. But not one problem getting it replaced. And so far, good battery life.

JoshuaZ · Aug 23, 2008, 12:03 PM

Originally Posted by -Q-

I just had to have mine replaced about a month ago for that exact same issue. It would say it has X% left, but would then just up and die. But not one problem getting it replaced. And so far, good battery life.

mmm.... I have a 16 hour plane flight home next week. Glad I have fully working battery to get me through some of it.

JoshuaZ · Jul 25, 2009, 10:10 PM

So I'm going to bring back this thread from the dead because I'm now back in the same boat.

Its been almost a full year now since I got my replacement battery from Apple, and I just happened to notice the other day that my computer died on me at 42%. Ok..... According to MiniBatteryLogger my battery is at 70% health after 33 cycles....

So I charged it all up and let it run down and once again when I hit 41% the computer cuts out. WTF? One bad battery is bad luck, two makes me think its something with my computer! Or the power supply.

Has anyone else had this problem in the past year? Is this a weird issue with the late 2007 Macbook Pros! CURSE YOU BATTERY!!!!

JoshuaZ · Jul 26, 2009, 12:44 AM

Scratch that. Now its cutting off at 65%.

Simon · Jul 26, 2009, 01:41 AM

So your battery is almost one year old and has 33 cycles. What is the remaining full charge capacity according to System Profiler?

And FTR, I'm on the third battery with a Mid 2007 MBP too.

JoshuaZ · Jul 28, 2009, 10:19 AM

Its oddly been going up and down between 3000 and 4000 max charge the last couple of days.

Though it keeps randomly shutting down (aka losing all power) with 45% charge remaining.

Damn batteries.

Simon · Jul 28, 2009, 11:31 AM

Yep, the battery is obviously broken. Contact Apple to see if you can get a replacement.

Spoffo · Aug 1, 2009, 02:02 PM

My MBP is almost 3 years old and has started suddenly cutting off without warning when battery level reaches about 90-91%. It only has 56 cycles on it, but the pattern of irregular use is probably as bad for a battery as is possible: sometimes stored away for moths at a time while the battery bleeds down to nothing. Other times, kept plugged in and used for several months without ever being discharged at all.

In researching this - and confirming that it's a shot battery even though it shows lots of charge - I got an educational response from Apple support that explains what's going on in cases like this.

"it's commonplace for a failing lithium battery not to give any low-battery warning, and then to exhaust its last iota of charge so abruptly that the machine it's powering just shuts down instead of going to sleep. If your battery is two years old and its 56 cycles have been very evenly distributed, every two weeks or so, then it's strange for the battery to be failing now as it seems to be doing. If the battery is three years old, or if it has ever been run on AC power for periods of many weeks or months without cycling, then its failure is pretty much to be expected.

A battery that doesn't get exercised enough may retain a high Full Charge Capacity (like yours), but develop so much internal resistance that it can't push its stored energy out efficiently to connected devices. I'm guessing that's the state of affairs in your battery. And I don't know exactly how the low battery warning system is activated, but it seems possible to me that you aren't getting a warning because your battery's remaining capacity actually isn't low, even when the computer shuts down for lack of power: only its *output* is low. If the system isn't designed to give a warning when the battery's capacity is high but its output is low, that would explain the lack of a warning in your case."