Long Term use in Dock

Discussion in 'MacBook Pro' started by Samuriajackon, Sep 28, 2009.

  1. Samuriajackon macrumors 6502

    Samuriajackon

    Joined:
    Feb 9, 2009
    #1
    with my MacBook listed below, i have a 19in Monitor, a mini-display to DVI/HDMi setup, a USB Hub with keyboard and mouse and natrually a power adapter all plugged in, what are long term sideffects of leaving this thing hooked up all the time. I know i need to run the battery down and recharge about once a week...am i going to hurt my laptop?

    I turned my screen to the dimmest settings to preserve the backlight? Good idea?
    :confused:
     
  2. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #2
    Why do you want to run down your battery weekly :confused:. Deep discharges shorten the life of the battery then anything else. I'd only run the battery down if the reporting charge status is not accurate, i.e., recalibrate the batttery.
     
  3. Samuriajackon thread starter macrumors 6502

    Samuriajackon

    Joined:
    Feb 9, 2009
    #3
    I had a battery on charge 100% of the time and it died after 6 months, does this not happen anymore?
     
  4. djarpit macrumors regular

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    Jun 9, 2009
    #4
    i am also interested in this.. as i am going to be doing this starting next week for my home studio.
     
  5. m85476585 macrumors 65816

    Joined:
    Feb 26, 2008
    #5
    That basically happened to me. Personally, I would try to use it on battery at least once a week. You don't have to go all the way to zero (in fact, it is probably better not to). I would discharge it to zero (calibrate) occasionally, maybe once every 1-2 months.

    Discharging too much will not be that bad for the battery. If you discharge to zero once a week, assuming the battery will last 300 cycles, it will last almost 6 years. The new battery is supposed to last 1000 cycles (we'll see), or 20 years at one cycle a week! Even if you do one full cycle every weekday it will last close to 4 years. If you use it on battery an hour a day and that drains it to 80%, it should also last 20 years based on cycles alone.

    If you don't mind a little extra noise, using SMCFanControl to keep the fans a little higher will extend the life of the battery (though possibly shorten the life f theo fans). The latest version of SMCFanControl also lets you set a fan speed for while the battery is charging, which you should set as high as you can tolerate because that's when the battery gets hottest. Make sure that wherever it is docked it has good airflow. A cooling pad might help.

    You have an LED backlight, so you shouldn't have to worry about that.
     
  6. jt2ga65 macrumors regular

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    Jul 1, 2007
    #6
    Modern batteries should not normally do that. This is more of an old ni-cad limitation, I think.

    -jt2
     
  7. m85476585 macrumors 65816

    Joined:
    Feb 26, 2008
    #8
    Modern lithium batteries will be damaged fairly quickly (6 months to a year) if you keep them at 100% charge, which is basically what happens if you leave it plugged in all the time.
    http://www.apple.com/batteries/notebooks.html
     
  8. Samuriajackon thread starter macrumors 6502

    Samuriajackon

    Joined:
    Feb 9, 2009
    #9
    If you click on the link above a page comes up warning that any temp above 95 F is poor conditions for operations...i went 4 months in Iraq where my poor White Book was over 110 F and running almost all the time...poor MacBook...
     
  9. sanPietro98 macrumors 6502a

    sanPietro98

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    May 30, 2008
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    #10
    There's no date on this article, but it mentions a "PowerBook." So is this still current with the latest battery technology?
     
  10. m85476585 macrumors 65816

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    Feb 26, 2008
    #11
    Yes. It also mentions Macbook Pro.
     
  11. jt2ga65 macrumors regular

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    Jul 1, 2007
    #12
    Wait... I thought that the computer would not even CHARGE the batteries unless they dropped below 95% charge. The power adapter switches from green to orange to indicate that it is charging the batteries. If the battery is charged, then the computer runs off of the AC power, rather than the battery, and the battery is not even in the circuit.

    If this is not the case, then Apple made a bad mistake making the batteries built-in. With the previous models, you could just have removed the batteries if you were worried about changing issues.

    -jt2
     
  12. m85476585 macrumors 65816

    Joined:
    Feb 26, 2008
    #13
    The battery is still in the circuit, that's why the computer keeps running if you pull the plug. When you removed the battery from a previous Apple laptop, they would underclock to half the normal speed for some reason. I guess the charger couldn't react quickly enough or supply enough power in some cases.
     
  13. jt2ga65 macrumors regular

    Joined:
    Jul 1, 2007
    #14
    Makes sense. Sort of like a hybrid car using the battery to help the car accelerate, but using the gas engine to sustain the vehicle's speed.

    I read the Apple article that was linked above, and it makes sense. I would have to say that the ability to cycle the battery once ever 1-2 months is a good idea, but unless you have the computer on UPS and generator, the likelyhood is good that this will happen anyways. The Apple article did not state that you needed to discharge completely, just that it was a good idea to keep the electrons moving through the battery.

    Mine gets charged about once a month, as I really hardly ever use it outside of my desk, table or living room chair. All of which have power and an adapter sitting there. It has had 94 cycles in not quite 2 years, but less than half a dozen that were more than 50%.

    -jt2ga65
     
  14. sn0warmy macrumors 6502a

    sn0warmy

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    Mar 26, 2009
    Location:
    Denver, CO
    #15
    I had my 1st generation Macbook Pro plugged in 95% of the time. I worked on it at least 6 hours a day. I probably let the battery completely drain only a handful of times. And even after 3 years the battery lasted over 2.5 hours.

    Supposedly these magsafe chargers cut off charge tot he battery after they are full. And based on my previous experience, I believe it.


    Just my $.02
     
  15. m85476585 macrumors 65816

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    Feb 26, 2008
    #16
    What's your battery health? (you can check with coconut battery)
     
  16. jt2ga65 macrumors regular

    Joined:
    Jul 1, 2007
    #17
    Looks like 95% health with 98% current charge. I could let it drop below 95% charge and recharge and see if this changes at all.

    It also claims that the battery is not currently charging, which is what I believed to be true due to the green light on the AC adapter.

    -jt2
     
  17. m85476585 macrumors 65816

    Joined:
    Feb 26, 2008
    #18
    Actually the charging circuit is in the laptop or the battery. It has to stop charging when it reaches 100% or your battery would probably catch on fire within an hour. NiCd batteries got a bad reputation for "memory" effects because most chargers back then were dumb and did not stop charging when the batteries were full. Overcharging basically boils the electrolyte, so the battery will no longer hold as much charge. NiMH batteries do better because most NiMH chargers are smart, and NiMH technology is better than NiCd. All lithium battery chargers are "smart" chargers that stop charging when the battery is full because they tend to catch on fire or explode if they are overcharged.

    The problem is that leaving the battery at 100% charge all the time degrades it. I don't know exactly what happens, but there is some chemical reaction that permanently degrades the battery. Charging and discharging somehow reduces this, as does storing the battery around 50% charge. If you ever buy a new battery for your MBP, you might notice that it comes charged about 50% (it might be anywhere from 40-60%). If you were to charge a lithium battery to 100% and let it sit for six months, it would degrade almost as much as if you kept it in your laptop plugged in most of the time for six months. (though not quite as much because it probably would not be as warm, and it would not be charged back to 100% as the charge slowly drops due to internal current leakage).
     
  18. neteng101 macrumors 65816

    Joined:
    Jan 7, 2009
    #19
    From what I notice, if you leave it charged at 100%, it doesn't stay there. It drops slowly to 95% over time, then the charging keeps it again. So it looks like even if you were connected 24/7, there is some sensible cycling going on.

    It doesn't try to keep the charge at 100% but lets the battery lose its charge slowly and then bumps it back up. See attached... notice its not charging?
     

    Attached Files:

  19. JRoDDz macrumors 68000

    JRoDDz

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    Jul 2, 2009
    Location:
    NJ
    #20
    Apple recommends charging and discharging its battery at least once per month.
     
  20. mapsk macrumors newbie

    Joined:
    Sep 29, 2009
    #21
    Cant be good how did it survive?
     

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