Santa Rosa Macbook Battery Q

Discussion in 'MacBook Pro' started by macdim, Nov 15, 2007.

  1. macdim macrumors 6502

    Oct 16, 2007
    Hey so I was just wondering:

    1. When the power adapter is plugged in, and the MacBook is charged (green light on magsafe plug), does the power adapter use any power other than to power that tiny little green LED?

    2. Is it better to unplug the MacBook after it is charged, or to keep it plugged in? Does it matter?

  2. mankar4 macrumors 6502a


    Aug 23, 2007
    1) I dont know. probably it does, at least to run the fan inside the block. (i believe there is one)

    2) leave it plugged in, definitely. you don't want to use your battery any more than you have to, as this will add cycles and reduce the maximum capacity of your battery. The power will bypass the battery once it is charged, so there is no problem with leaving it plugged in.
  3. Anonymous Freak macrumors 603

    Anonymous Freak

    Dec 12, 2002
    1. Yes. All 'power bricks' use a few Watts of electricity merely being plugged in, even if they aren't plugged into their device. So if you leave your power adapter plugged in to the mains power, then even while you are away, it is using a little power.

    2. If you are going to leave your computer off, and I mean all the way off, not just asleep, then leave it plugged in for an extra 2 hours after it is fully charged, then unplug it. It will 'trickle charge' for a few hours after it says "full", but even after that, it will still use some power.

    If you want to use the least energy possible to recharge your MacBook, then leave your power adapter unplugged until you are ready to plug in your computer, turn your computer off, plug it in, and unplug it from both the computer and the wall as soon as the light turns green. You will only have charged the battery to about 90% full, but the remaining 10% takes more power per % to charge than the first 90%.

    Of course, if you're going to these extremes, then make sure to do this for everything in your house that uses a transformer (aka "power brick".) And make sure to unplug any appliances that you aren't actively using, like your TV or VCR. Make sure to keep your freezer as full as you can, as freezers are more efficient when full; but DON'T completely pack your refrigerator, because for some reason, they are LESS efficient when full.) Replace every light bulb in your house with compact fluorescent (or even better, LED,) and turn them off every time you leave the room.

    Unless you are trying to be an absolute power-miser (for example, if you live off the power grid, and use solar panels for all your electricity,) there is no reason to go to these extremes. If you have even one standard incandescent lightbulb, it is using more power (than if you had a compact fluorescent,) than leaving your MacBook plugged in even after it is fully charged.
  4. macdim thread starter macrumors 6502

    Oct 16, 2007
    Thanks to both of you for your responses. I leave the computer fully turned off (not sleeping) most of the time since the boot times really are minimal. I'm not a real power miser so I don't really care too much about that. As long as it isn't using an inordinate amount of power for no reason, I'm fine with that.

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