Help: Battery shut down at 40% charge

Discussion in 'MacBook Pro' started by airfrancisco, Apr 30, 2009.

  1. airfrancisco macrumors regular

    Mar 16, 2005
    I'll try to explain the situations as much as I can so maybe you guys can understand why it does this behavior.

    Just recently my battery just shut down when my battery charge was at 40% without warning. When I charge it, it says 0%. How did that happened? How did it drop 40% in a blink?

    I tried what others are saying here such as resetting the SMC with battery and AC adapter taken out and press the power button for 5 secs. That didn't work. I even calibrated the battery and that helps the battery a bit, but still shut down without warning. Is now a good time to invest in new battery?

    To help you guys, my macbook pro is 15" 2.33gHz and life cycle on battery is at 228. Thanks and any info will be greatly appreciated.
  2. jjprusk macrumors member

    Jul 20, 2007
    RE: Help: Battery shut down at 40% charge

    I had this happen to my 17" Macbook Pro. The system was almost 3 years old (I don't remember the # of cycles, but well used...) and it suddenly started shutting down around 40% charge. I lived with this for a little while (as I didn't have time to deal with it) and then the battery became "swollen" (ie, it expanded and cracked open the battery case). I, fortunately, had Applecare and the system was just under 3 years old so they simply sent me a new battery in exchange for the old one. My guess is that your battery will go through the same process and I'd be careful as it will "swell". My swollen battery didn't leak acid or anything really bad, but I suppose that could happen in a more extreme case.
  3. NATO macrumors 68000


    Feb 14, 2005
    Northern Ireland
    Try rebooting, holding down cmd+shift+P+R until you hear it chime a second time. That sorted out a problem I had with my old MBP which sounds very similar.
  4. thedarkhorse macrumors 6502a

    Sep 13, 2007
    This is actually a common problem, at least for me.
    Mine had this problem but with only like 36 cycles and out of warranty, it would last less than 5 minutes on battery power before shutting off without warning. Apple has or had on their site a page about battery recalls with issues on batteries under 300 cycle counts and mine fit the criteria so it said to take it into a repair center, I did that and they checked the serial but apparently mine wasn't covered under the recall even though it had the exact symptoms of the recalled ones. With no money at the time I had to just bite it and use my MBP on AC forever until yesterday when I finally bought a new battery.
    Maybe you'll be lucky, take it in and get it checked to see if your serial is one of the recalled batteries, you're supposed to get a free new one if so, if not you gotta pay like me.
  5. airfrancisco thread starter macrumors regular

    Mar 16, 2005
    Thanks everyone. Glad that I'm not the only one with this problem. I'll try to stop by apple store and get it check out.
  6. airfrancisco thread starter macrumors regular

    Mar 16, 2005
    After checking with coconutBattery, here's my info

    Current Battery Capacity: 3582 mAh
    Original Battery Capacity: 5500 mAh

    Battery Loadcycles: 228

    Is now a good time to invest into new battery?
  7. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    Yes. By the looks of it, you're almost reaching 300 cycles so you should start seeing a bit of your battery life decrease.

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