11 Replies Latest reply: Jan 12, 2010 3:18 PM by ArinS
Rincewind84 Level 1 Level 1 (0 points)

I recently replaced my old Desktop PC with a 13" Macbook Pro so I could get rid of the massive tower and save some desk space. To save more space I purchased the rather attractive Twelve South Bookarc and now connect my old monitor, keyboard and mouse to the MBP:


I was really annoyed to find out that the MBP must have the AC power cord connected to operate in Clamshell mode. Does anyone know why Apple force this on you?

There is no denying that this will ruin the battery life on my MBP because it will remain plugged in 24x7. Is there any way to reconfigure the mac so that it will run in Clamshell mode without the AC connected.....like any regular laptop?

Any help would be greatly appreciated.


MacBook Pro 13", Mac OS X (10.6.2), 500GB HDD, 2GB RAM
  • eww Level 9 Level 9 (52,975 points)
    No, there isn't.
  • ArinS Level 1 Level 1 (0 points)
    If you have the earlier version then you can try to remove the battery and connect the AC. But even that is not suggested by Apple saying that the CPU will run without the full capacity.
  • Rincewind84 Level 1 Level 1 (0 points)
    I have a Macbook as well, the older white model, but I'm not keen on removing the battery and leaving the AC plugged in.

    I just don't get it, it's such a stupid design, and it is a little surprising coming from Apple.

    As an alternative, I've heard of background apps you can install that prevent the Mac from sleeping. In turn allowing you to disconnect the power cord. Anyone tried that?
  • Allan Leedy Level 2 Level 2 (245 points)
    What's the big deal? Just leave it plugged in. If you want to follow Apple's recommendation on battery maintenance, you can discharge it once or twice a month.
  • eww Level 9 Level 9 (52,975 points)
    If you have no use for a portable computer, why didn't you save half or 2/3 of the MBP's price and buy a Mac Mini instead?
  • Rincewind84 Level 1 Level 1 (0 points)
    I was torn between the MacMini and the MBP but looking at the specs, they were both almost identical. So I paid the extra for the convenience of being able to take my new mac away from my desk. Plus my other half and I were always fighting over custody of my old MacBook which sits downstairs. Now I have the abilty to take the MBP downstairs instead of being confined to my desk upstairs when the other MacBook is occupied.

    Anyway I don't see how this is relvant to my current predicament. 

    I guess the chances of Apple rolling out a firmware update to sort this put are pretty slim so I guess a third party hack/app is the only way. Unless someone knows how to disable the sleep function in the OS somewhere?   
  • Network 23 Level 6 Level 6 (11,875 points)
    Rincewind84 wrote:
    There is no denying that this will ruin the battery life on my MBP because it will remain plugged in 24x7.

    The only way leaving it plugged in will shorten battery life is if the battery is both hot and at 100% charge, and you don't calibrate it once a month or so. Simply leaving it plugged in is not a problem by itself. Lithium-ion does not have a memory and the circuitry will not allow overcharge.

    You should try running an external monitor in lid open mode and on battery. The battery drains very quickly that way and you won't be very happy. That's why Apple makes you plug it in.
  • eww Level 9 Level 9 (52,975 points)
    Anyway I don't see how this is relevant to my current predicament.

    If you intend to use the MBP as a portable computer on occasion, running it on battery power when you do, you won't need to worry about your original strident objection to the AC power requirement for clamshell mode:

    There is no denying that this will ruin the battery life on my MBP because it will remain plugged in 24x7.

    Of course if the machine were to remain plugged in all the time, it wouldn't make the slightest difference to you if its battery was ruined. You'd never need the battery.

    So use it in clamshell mode most of the time, and once a month, unplug it, run the battery down and recalibrate it. You will be within the letter of Apple's advice on managing the battery, and you'll have nothing to worry about. It's only if you can't manage this minimal inconvenience that you'll have to regret your decision to buy a MBP instead of a Mini.

    An anti-sleep hack won't turn off the built-in display when it's closed, as clamshell mode does, and it may prevent the machine from going to sleep for its own protection if it ever overheats, which is more likely with the display closed than open.

    Message was edited by: eww
  • ArinS Level 1 Level 1 (0 points)
    Everybody has their own reasons behind their purchases. There might be periods of time when someone would keep the laptop only at his/her home. Anyways, I think there is something fishy here with the CPU capacity, but it is something I have accepted before purchasing the product.
  • eww Level 9 Level 9 (52,975 points)
    ...I think there is something fishy here with the CPU capacity...

    It's not completely clear what you're referring to here, but if you're wondering why the CPU is throttled back when you remove the battery, it's because under some extremely high-load circumstances the machine can require more power than the AC adapter is able to provide. At such times it automatically draws on the battery to make up the difference. If it were to call on the battery and no battery were present, the machine would suddenly shut down, losing any unsaved work that was open. To prevent that, when you remove the battery, the processor is slowed down enough so it can't exceed the power output of the AC adapter alone.
  • ArinS Level 1 Level 1 (0 points)
    Yes that sounds reasonable; I did not know that this was actually possible. The reasoning behind their statement is along the lines of "The AC cord could become easily unplugged and computer might be damaged.", which never happened to me when using PCs. But anyways, this is something that I had accepted.