Removing SATA optical drive for...battery?

Discussion in 'MacBook Pro' started by Techhie, Jun 12, 2009.

  1. Techhie macrumors 65816

    Techhie

    Joined:
    Dec 7, 2008
    Location:
    The hub of stupidity
    #1
    Let's say hypothetically I knew someone with some soldering and mechanical skills. I know that it is possible to replace the SuperDrive with an extra SATA Hard Drive, but is it possible to use that space for other reasons? If someone were to take the new non-removable battery, and solder a connector from it to another "battery" (non Apple, one that fits the space), would the laptop be able to recognize it as a single power source? I know some hardware and software dabbling is required here, but I was wondering if it was feasible.

    thanks
     
  2. BittenApple macrumors 6502a

    BittenApple

    Joined:
    Nov 29, 2008
  3. m85476585 macrumors 65816

    Joined:
    Feb 26, 2008
    #3
    It won't work. The battery isn't just a normal battery like a AA battery. It has several battery cells wired together, all connected to special internal circuitry. The circuitry monitors the health, charges the battery, prevents extreme conditions (short circuit, high temperature), and probably authenticates it so you can only use genuine Apple batteries (or fake ones with a hacked chip). Connecting another battery will not work. If you connect it directly to where the built-in battery puts out power (like the + and - terminals), you are asking for all kinds of trouble. Connecting lithium batteries in parallel is a bad idea without protection and balancing circuitry, and you could cause a fire. At the very least, you will probably fry the chip in the built-in battery or the charging circuit in the laptop since they are not designed to have another battery present. If you fry anything in the laptop, it will need a new logic board, which is expensive out of warranty, and since you damaged it yourself, probably not covered by warranty even if you have Apple Care. The soldering will be obvious when they take the laptop apart unless you are very skilled in soldering rework.

    The only way I can think of that would make this work is to have a custom battery built in the shape of the original battery plus the optical drive, with all the usual internal circuitry custom designed to support the extra capacity. Even then, you might run into trouble if Apple batteries do any kind of authentication to prevent "fake" batteries. I don't know enough about how Apple's batteries are built to say if it is possible. Even if you are successful, you won't get the 1000 cycle capacity Apple claims unless you can find out who makes their special battery cells, as normal li-poly cells will only last 300-500 cycles.
     

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