Does power loss damage batteryless MBP ??

Discussion in 'Mac Basics and Help' started by brasiliangringo, Feb 18, 2009.

  1. brasiliangringo macrumors regular

    Feb 18, 2009

    I run MBP without battery 99% of the time to safe its 300 or so cycles and I occasionally trip the mac safe adapter (which i find gimmicky and annoying) by maneuvering MBP around when sitting down & the cable gets snagged momentarily on corner of coffee table etc and out goes the power !!

    Is this causing any damage ?!? I havent noticed any ill effects.

    I also understand from reading other threads how the processor speed reduces without battery but thats ok considering most of my use is limited to web browsing..

    Thanks , N .
  2. spinnerlys Guest


    Sep 7, 2008
    forlod bygningen
    It could damage your hard drive, as the read/write head may be moving over the platters and crashing onto them when there's no power to hold it in its place.

    Modern batteries should do more than fine if left inside the computer, and as it seems to happen often that you trip over the power cord, I would say you are safer by letting the battery stay inside the MBP.

    What damage it can do to your other internal components I can't quite say.
    Maybe the sudden power surge could damage some other parts too.
  3. portent macrumors 6502a

    Feb 17, 2004

    Okay, let's do some math, shall we?

    We have 300 cycles. The MacBook doesn't charge until it reaches 95%, at which point it will recharge by that 5% of a cycle. So we get
    300 / 0.05 = 6000

    With only internal resistance (eg. not using the battery at all) I would say that it takes perhaps a week for it to lose that 5%.
    So 6000 * 7 = 42,000 days, or a little over 115 years.

    So, between now and 2124, you will have saved yourself the cost of a $129 battery. I'm sure your great grandchildren will thank you.
  4. claimed4all macrumors 6502

    Sep 26, 2008
    Nice math. With today's technologies there is no reason to remove the battery. It probably does more damage by removing and reinserting it all of the time.
  5. Darth.Titan macrumors 68030


    Oct 31, 2007
    Austin, TX
    Also to the OP, you are aware that the MacBooks will throttle down performance by as much as 37% if you are operating on AC with no battery installed. Apple documents this themselves.
  6. brasiliangringo thread starter macrumors regular

    Feb 18, 2009
    So, between now and 2124, you will have saved yourself the cost of a $129 battery. I'm sure your great grandchildren will thank you.[/QUOTE]

    Great grandchildren - if only i where so old and wise ;)

    Thanks for your reply and everyone elses, but does battery memory deteriorate if you run mains power through it constantly or is the downside marginal ?
  7. energysaver macrumors newbie

    Feb 18, 2009
    These li-ion batteries are optimised to work inside the computer.

    Also, the computer itself will probably only last a few years before you get a new one, so does it really matter?

    And if you always use it plugged in and most of your work is "web browsing", why are you so protective of the battery that you never use?
  8. MAGICMOXTER macrumors regular

    Feb 16, 2009
    By leaving the battery outside of the computer you shorten its life more than leaving it in. The only way to properly preserve it is to take it out of the computer with 40% charge and put it in the freezer.
  9. brasiliangringo thread starter macrumors regular

    Feb 18, 2009
    Thanks energysaver,

    It is my friend's mac except i currently use it all of the time so feel obliged to give her the opportunity to be the one (eventually..) to wear the battery down - although my original concern about battery wear now seems unfounded given the replies !!

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