Should i unplug when fully charged?

Discussion in 'MacBook Pro' started by melodosgr, Oct 19, 2010.

  1. macrumors newbie

    Joined:
    Feb 25, 2010
    #1
    Hello everyone!

    I have the impression that my MBP still charges when the power lead is hooked into my macbook. Is that true? Do i have to unplug the power cord each time my macbook is charged? Is there any way that the battery life might be affected?

    I hope there is some sort of a circuit involved, that stops charging the battery when the battery is full, rather than overcharging it..

    Thanks!
     
  2. Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #2
  3. macrumors member

    Joined:
    Aug 29, 2010
    #3
    Not always. I almost always charge it to 100% and then unplug it once it's charged, run the battery down to below 10%, and then repeat. My 2007 White MacBook has 1,745 cycles and around 95%-99% health.

    However, you don't need to disconnect it... the MacBook will stop charging once it's charged.
     
  4. Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #4
    Wow, you've got one fantastic battery, though I read of similar behaviours and it led to batteries being at less than 50% health with less than 500 cycles.
     
  5. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #5
    That is definitely NOT the way to treat a battery! You are circumventing Apple's built-in protection against this kind of charging.
    If you haven't calibrated properly, your health readings are likely incorrect.

    I strongly encourage you to read the FAQ link that spinnerlys posted.
     
  6. macrumors member

    Joined:
    Aug 29, 2010
    #6
    I think it's all about conditioning it to be used to its full potential, so letting it drain down and charge up helps. Here's a screenshot I just took.

    So far so good for me. How's your battery doing?


    [​IMG]
     
  7. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #7
    Have you calibrated properly? If not, your readings are meaningless.
     
  8. macrumors member

    Joined:
    Aug 29, 2010
    #8
    Yup. Still lasts me almost just as long as when it was brand new!
     
  9. macrumors newbie

    Joined:
    May 2, 2010
    #9
    When the battery is fully charged the charging circuit in the laptop stops charging. You do not need to disconnect the AC adapter when the battery is full. A lithium battery's life is shortened when it is deep discharged. To prolong the life of the battery, it's best to keep the battery charged and avoid draining it down.

    After repeated charging the software battery meter can get out of sync with the actual state of the battery. This is the only reason to purposely run down the battery. When the battery is complete run down, the battery meter can calibrate empty to the battery's actual empty voltage. Many people misinterpret this and think that discharging is somehow good for the battery.

    But this is all just battery optimization, don't let it impact the way you live your life. Just keep it connected to the AC adapter when possible, and run off battery when you're on the go. The worse case is that you'll need a new battery in 3 years.

    Steve
     

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