Battery Life - Cycles?

Discussion in 'MacBook Pro' started by harcosparky, May 7, 2009.

  1. harcosparky macrumors 68020

    Jan 14, 2008
    I read about battery capacity versus " # of cycles ".

    What exactly constitutes a " cycle "?

    Do you have to run the batter down to a certain level and then charge it to count as a 'cycle'?

    Is running the laptop with battery in and AC adapter on the best way to insure a long life? You know, run the laptop on battery power when it is needed, and not just because you can.

    I used to think I knew about this, but after reading several threads/posts I have to wonder! :confused:
  2. jackiecanev2 macrumors 65816


    Jul 6, 2007
    Wirelessly posted (BB 8900: BlackBerry8900/ Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/301)

    A cycle is one complete discharge. Discharge cycles are cumulative (ie, 50% discharge, + 20%discharge, + 30% discharge = 1 charge cycle). And no, it is not better to leave your battery on the charger all the time; batteries need to have their cells charged and discharged regularly to keep them at their peak holding capacity.
  3. AppleNewton macrumors 68000


    Apr 3, 2007
    1 Finite Place
    Its best to let the battery discharge a bit and let it flux.
    the technologies in the new apple batteries are pretty good so they dont need too much calibration techniques.

    My 17" is almost always plugged in and at about 4 cycles now the battery life and over charge capacity has gone over 13000+ from 12005~ and too 100% from 96% health.

    I usually let it drain a while by unplugging it when im working and then allow it to charge back up once it hits around 75-80%

    it also does a pretty good job while in sleep mode...and my charge capacity went up a few notches aswell when i left it charging over night.

    just keep it steady and just be sure to use the system...i woulndt worry too much about some of the numbers...atleast do a few minimal discharges a week (ie; drain to about 70-80% and let it fully charge) and atleast 1 full discharge (ie; drain to 0% & let it go into sleep mode and recharge to 100%) once a month.

    discharges are also counted in if you discharge to 70% and then you go back up to 100% then you drain 30% and go back upto 100% i believe that counts as a full cycle anytime it constitutes 100% charge/discharge is when you will get your cycles.
    just from my observations...
    but really the new batteries dont need too much done to them..but hope that helped a bit.
  4. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    What I do is fully discharge the battery every 2 days. Have it plugged in, 2 days later completely drain it and charge it back up again.
  5. ZMacintosh macrumors 65816


    Nov 13, 2008
    seems a bit excessive......?

    once a week isnt that bad ...which what I usually tend to do full 100 to 0 and back.
  6. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    Not really. I'm not one of those who thinks their battery is gonna last forever. Knowing that once a battery is near 300 charges, battery life is gonna suffer. My method (once every 2 days) will allow me to get life for more than a year - which I'm perfectly fine with, probably going to need a new one after a year anyway.
  7. marina330 macrumors newbie

    May 11, 2009
    Batteries life is determined in Cycles. 1 Cycle equal 1 discharge + 1 charge.The Lithium-Ion batteries used in notebooks are rated to handle between 300 and 800 charge/discharge cycles. After all,the battery is going to dead some day no matter how coutious you use it. And a spare one maybe useful. There are tons on ebay.Another site maybe useful:

Share This Page