OVERCHARGING THE MAC?

Discussion in 'OS X Yosemite (10.10)' started by kayleee, Jul 19, 2015.

  1. kayleee macrumors regular

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    Nov 20, 2013
    #1
    Takes about 1 hour to go from 0% to 100% ,it gets really hot while charging...normal right?

    but when i leave it overnight in the morning or even at midnight when its done churning showing the green indicator, the mac and charger is VERY COOL, like normal when not charging.

    SO, is it dangerous to keep it charging overnight? I don't mean dangerous, but not good for the battery?

    I guess no?
    Because its detecting its fully charged and in a way seems to DISABLE charging , keeping the MAC cool and not letting it heat.

    Any thoughts?

    Should I leave it overnight?
    Charges full in 1 hour
    But i cannot wake up to turn to off
    I turn it off in 6 hours when I wake up.

    Not recommended/recommended?
     
  2. Ice-Cube macrumors 6502a

    Ice-Cube

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    #2
    It's okay to leave it charged. What really shortens the battery life is heat and number of cycles it goes through. Charging it from 0% to 100% is one cycle, 50% to 100% is half a cycle and each battery has a maximum number of cycles before it drops to 70-80% efficiency. Bottomline: charge as often as you can.
     
  3. Weaselboy Moderator

    Weaselboy

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    #3
    That is exactly what happens. It won't hurt a thing to leave it plugged in all the time.
     
  4. Gav2k macrumors G3

    Gav2k

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    Jul 24, 2009
    #4
    1 hour to go from 0-100% tells me somethings wrong!
     
  5. kayleee thread starter macrumors regular

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    Nov 20, 2013
    #5
    really?
    its 2013 macbook air and its been the same way since 2 years, BTW when I charge its in sleep mode not in use

    anything wrong?
     
  6. Gav2k, Jul 20, 2015
    Last edited: Jul 20, 2015

    Gav2k macrumors G3

    Gav2k

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    Jul 24, 2009
    #6
    To charge a battery that quickly something would have to be wrong mate. It's not possible to charge the battery that quickly from flat.

    If I remember correctly my 13" mba took about 45 minutes to 80% then 45 minutes for the last part. That was powered off with a random check. 11"2014 was the same to be honest.

    If it was on and idle it was approx 2 hours
     
  7. kayleee thread starter macrumors regular

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    Nov 20, 2013
    #7
    W
    Well its been the same since 2 years now, 1 year remixing for apple care lol
    if theres something wrong, what can it be?

    should i take it to apple care?

    works perfectly though, for 7-8 hours on good use
     
  8. border terrier macrumors regular

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    England
    #8
    I don't believe this is correct. Apple Support told me I must allow the battery to cycle through charge and discharge and not leave it plugged in all the time. I was told that this will hurt the battery. I've seen this many times on pc laptops too. Oh and don't shoot the messenger, just repeating what 2nd line support told me.

    FWIW I used a 2011 MBP for 3 years in this way including 2 years of daily business use. When I sold it the battery was still at 78%.
     
  9. kayleee thread starter macrumors regular

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    Nov 20, 2013
    #9
    Well brother what do you recommend we should do to get results like yours?
     
  10. Weaselboy Moderator

    Weaselboy

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    #10
    The Apple support person who told you that is incorrect. All that does is add unnecessary cycles to the battery. The old Apple support documents did include something about making sure you use the battery occasionally like you described, but that is no longer the case.

    http://support.apple.com/kb/HT1446

    http://www.apple.com/batteries/

    These two links are the official Apple information on batteries.
     
  11. Toutou macrumors 6502a

    Toutou

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  12. Linuxpro macrumors regular

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  13. kayleee thread starter macrumors regular

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    Nov 20, 2013
    #13
    next time check it when its CHARGING, i'm sure it gets hot for almost all of us while charging.
     
  14. border terrier macrumors regular

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    #14
    These links don't mention whether it's OK or no to leave a laptop charging. This link http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries however suggests.....

    "a regular Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. When fully charged, remove the battery and allow to voltage to revert to a more natural level. This is like relaxing the muscles after strenuous exercise. Although a properly functioning Li-ion charger will terminate charge when the battery is full, some chargers apply a topping charge if the battery terminal voltage drops to a given level"

    and here http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries states.....

    "Li-ion cannot absorb overcharge, and when fully charged the charge current must be cut off. A continuous trickle charge (maintenance charge) would cause plating of metallic lithium, and this could compromise safety. To minimize stress, keep the lithium-ion battery at the 4.20V/cell peak voltage as short a time as possible."

    and...

    "If a lithium-ion battery must be left in the charger for operational readiness, some chargers apply a brief topping charge to compensate for the small self-discharge the battery and its protective circuit consume. The charger may kick in when the open-circuit voltage drops to 4.05V/cell and turn off again at 4.20V/cell. Chargers made for operational readiness, or standby mode, often let the battery voltage drop to 4.00V/cell and recharge to only 4.05V/cell instead of the full 4.20V/cell. This reduces voltage-related stress and prolongs battery life.

    Some portable devices sit in a charge cradle in the on position. The current drawn through the device is called the parasitic load and can distort the charge cycle. Battery manufacturers advise against parasitic load while charging because it induces mini-cycles, but this cannot always be avoided; a laptop connected to the AC main is such a case. The battery is being charged to 4.20V/cell and then discharged by the device. The stress level on the battery is high because the cycles occur at the 4.20V/cell threshold, often also at elevated temperature
    .

    A portable device should be turned off during charge. This allows the battery to reach the set threshold voltage unhindered and termination on current saturation. A parasitic load confuses the charger by depressing the battery voltage and preventing the current in the saturation stage to drop low. A battery may be fully charged, but the prevailing conditions will prompt a continued charge, causing stress.
    "

    Seems clear to me. Top up the battery often and do not leave the device permanently plugged in. If you can, turn the device off whilst charging.
     
  15. Toutou macrumors 6502a

    Toutou

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    #15
    I bought a MacBook to use it the way I like. The battery is protected by its own protective circuit and the system is pretty intelligent - it doesn't overcharge and there isn't any kind of "maintenance charge" - it just stops charging and waits until the charge drops by itself (not by direct usage - the MacBook is still plugged in and runs on external power).
    And no, no way I'm going to turn it off just because it's charging. :cool:
     
  16. ABC5S macrumors 68040

    ABC5S

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    #16

    I'll go by what Apple suggest, not your older non Apple links you provided. Never a problem with any Apple battery computer I have.
     
  17. Weaselboy Moderator

    Weaselboy

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    #17
    It is not mentioned on the Apple site, because it is not needed. I'll go with the official Apple web site's recommendations.
     
  18. Linuxpro macrumors regular

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    Singapore
    #18
    I am traveling in China right now. I used my macbook for a few hours when i was writing a document. I am sitting here with the power cable plugged in. It has been charging for about 15 min. The bottom is only a little warm.
     

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