My friend gave me his laptop which is Apple laptop A1286 (MacBook Pro 15") with the charger but the head of the charger was cut. I tried to charge with another charger but, it doesn't charge.

Now, I want to remove the battery to charge it with external charger. What I mean is, to use the original charger and use the the (+)wire to the positive side in the battery and the (-)wire to the negative, but when I removed the battery I found many black wires and I didn't know which ones are positive/negative.

If anyone can help me with this issue or any way to charge the laptop without using the home of the charger on my laptop?

If I will charge the battery I will be able to reconnected again and check if it will work or the motherboard is damaged.

  • which model? also, what is the battery - some pictures may explain what you mean by the "many black wires"
    – Solar Mike
    Sep 19, 2017 at 14:17

2 Answers 2


The positive (+) and negative (-) terminals on the battery are usually the outermost pins. Knowing the specific MacBook model is helpful here.

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The MagSafe 1/2 charger outputs 16.5 volts, so you are going to need a charger that supplies that amount.

Now, with all of that said.....

I highly urge caution in attempting to hack a DIY charger for your MacBook Pro battery.

If you don't have the necessary electronics diagnostic/repair skills, this is not something you should be attempting. Besides, there is a more safe and reliable way to diagnose your problems...

You don't need a battery to test out your MacBook.

If you have a MacBook (any model - Pro, Air, etc.) that will not turn on even with the battery disconnected, the problem is with the DC-In board or the logic board itself. And even before you begin this diagnostic journey, you need to make sure that the MagSafe charger you are using is functioning properly. A dead AC adapter won't charge any battery regardless if it's in the laptop or not.


have a look onto this file, it may help, it is hacking macbook pro battery https://media.blackhat.com/bh-us-11/Miller/BH_US_11_Miller_Battery_Firmware_Public_WP.pdf if you have TI Board BQ20Z80EVM, you may connect the battery externally, but please dig inside it more.

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