MacBook Pro needs broken battery to start

Discussion in 'MacBook Pro' started by hermagerd, Dec 20, 2014.

  1. hermagerd, Dec 20, 2014
    Last edited: Dec 20, 2014

    hermagerd macrumors newbie

    Dec 20, 2014

    I have a MacBook Pro 2012, with a broken battery. The battery is in good condition otherwise (30 cykles) but unfortunately it was left to unload completely for half a year or something. My next project is to see what i can do about that.

    The big problem now is that since the battery was completely empty, like literally 0 charge, "replace now" and "Battery is not charging" I removed it. Then I realized that my MacBook wont turn on without it when I have my adapter plugged in. It tries to start but dies before the screen comes on, regardless of what hardware is plugged in. It dies within some seconds even with just the fan connected.

    How is it possible that i need an empty, broken battery plugged in to be able to use the computer? Could it mean there is a spark of life in it, or is it something apple made up to make sure I'll pay for a replacement one?

    (Sorry for any bad English, not my native language)
  2. TheIguana macrumors 6502a


    Sep 26, 2004
    Take it to Apple, buy a battery.

    Newer MacBooks will not boot without a battery present that has at least 15% remaining life in it. Prior to recent MacBooks, the computer would under clock significant when running without a battery.

    Apple has explained it in the past as a safety feature for the hardware, as in maximum usage scenarios the system will pull power from both the AC adapter and battery.
  3. hermagerd thread starter macrumors newbie

    Dec 20, 2014
    Thanks for the answer! Then i will have to install the battery again until i can fix it or find a replacement one. Still it is a bit odd since my battery has 0% charge and refuses to charge and charge remaining is 0 mA.

    Any ideas of how to fix a deeply discharged battery? I was thinking of putting it in the freezer over night, it should at least do something.
  4. sevoneone macrumors 6502

    May 16, 2010
    Most lithium based batteries have an onboard chip that monitors the battery at all times for warning signs that the battery may fail. One of the things it monitors is the voltage level. Once the voltage passes below a certain point, the risk of a catastrophic failure while attempting to recharge the battery goes way up. The chip will prevent the battery from charging after that as a safety feature, even if the voltage in the battery goes back up on it's own. So the freezer trick will not work.

    There are ways to force charge a discharged lithium battery by applying a very low-amp charge over a long period, but it really isn't worth the risk of starting a very hot and violent fire.
  5. hermagerd, Dec 21, 2014
    Last edited: Dec 21, 2014

    hermagerd thread starter macrumors newbie

    Dec 20, 2014
    Thanks for the information!

    Just because I'm too curious:

    If i would manage to charge it slowly until usable, could it charge normally in the computer afterwards or would it always require me to take it out and charge it separately? Could i reset the chip somehow to make it charge normally again?

    Is there a permanent risk of fire when using the battery, or only when i charge it externally?

    I'd like to do something similar to this, but without having to open up the battery:

    TLDR; Can I do this anyway or will I die in a fire at night?
  6. hermagerd thread starter macrumors newbie

    Dec 20, 2014
    Another thing:

    It does not always start when the battery in plugged in, sometimes it takes a few tries. Once on it works perfectly.

    However, I can start it reliably without the battery by holding down the power button, connecting the adapter and then release the power button after a while. When I do like this it works perfectly, except for the fan running like crazy, and I can't get any temperature information from the indicators. Also the adapter indicator does not light up.

    I was aware of the fan issue since it was mentioned in the instructions to bypass the SMC, but can I run it like this and download a program to set the fan speed manually? Will it harm the computer, or will there be a risk of overheating since I can't measure the CPU temperature?

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