battery cycles

Discussion in 'MacBook Pro' started by Keytachi, Dec 26, 2006.

  1. Keytachi macrumors regular

    Joined:
    Sep 14, 2006
    #1
    can someone explain this to me? what an i supposed to do?
    (just got a macbok 2.00GHz for xmas :D)
     
  2. mad jew Moderator emeritus

    mad jew

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    Apr 3, 2004
    Location:
    Adelaide, Australia
    #2
    Explain what? A battery cycle is when you completely discharge a battery and then charge it back up. Each battery is limited to a certain number of cycles before it stops working. Try to avoid cycling your battery too much by leaving it on the adaptor when possible. However, to ensure your battery doesn't get over or undercharged, calibrate it monthly or so. :)
     
  3. Keytachi thread starter macrumors regular

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    Sep 14, 2006
    #3
    so you are saying that i should always keep my macbok plugged in? but wont that break the battery(like in the cell phones)?
     
  4. Temujin macrumors 6502a

    Temujin

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    Oct 1, 2005
    Location:
    Copenhagen
    #4
    When plugged in the battery isn't being used. So no it will not damage or break the battery.
    Don't know where you got the stuff about cell phones from. News to me.
     
  5. pianoman macrumors 68000

    pianoman

    Joined:
    May 31, 2006
    #5
    leaving certain cell phones plugged in can make the battery wear out more quickly than if you charge them then completely discharge before recharging.

    this is not the case with Apple notebooks. you should leave it plugged in all the time if you can; if you need to use it on the road (it is, after all, a portable computer), don't worry about wearing out the battery. follow the advice about calibrating it every month or so and you'll maximize the battery's life.
     
  6. dr427 macrumors regular

    dr427

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    Oklahoma City
    #6
    Get Coconut Battery to help you manage the battery. It is free. Just google it.
     
  7. aquajet macrumors 68020

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    Feb 12, 2005
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    VA
    #7
    No, you shouldn't. You shouldn't keep lithium ion batteries full of electrons all of the time. This will in fact degrade the battery faster.

    Lithium ion batteries are designed to be used. If you read Apple's battery usage guidelines carefully, you'll notice that ideal usage involves running your laptop on battery power on a regular basis (i.e. while you're away from your desk), and plug it in when necessary. They also recommend that you run it off the battery at least once a month.
     
  8. mad jew Moderator emeritus

    mad jew

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    #8
    Very good point, but I thought Apple's batteries were only ever calibrated to 97% of their actual capacity (could have the figure slightly wrong) to ensure the cells were never completely full. For the past year or so I've had my iBook almost permanently plugged into the wall, but I've calibrated it once a month. I've noticed no significant drop off in capacity those times I actually use the battery. :)
     
  9. Mac'Mo macrumors 6502a

    Mac'Mo

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    NYC
    #9
    i think a battery cycle is how many times the battery has been fully drained and recharged
     
  10. smueboy macrumors 6502a

    smueboy

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    Oct 30, 2006
    Location:
    Oz
    #10
    As per apples instructions (http://www.apple.com/batteries/notebooks.html):

    "For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month."

    I try to use mine on battery at least once or twice per week, and calibrate it every few months.
     
  11. Neoraven macrumors member

    Joined:
    Nov 18, 2006
    #11
    [​IMG][/IMG]

    From the screenshot, does that mean I need to calibrate the battery when its currently above its own maximum? Or a defect in the program?
     
  12. pdham macrumors member

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    Jan 28, 2003
    Location:
    Madison
    #12
    I just downloaded Coconut. My MacBook is only 3 months old and it says I have lot 9% of my max battery capacity already. Whats the deal? I use it on battery primarily, and charge it when necesary. It has completely drained (to the point of shuttinf off while on sleep) and recharged three times. Any thoughts?
     
  13. Jiddick ExRex macrumors 65816

    Jiddick ExRex

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    #13
    That might the reason. The Lithium-Ion batteries only have a limited number of cycles, so if you use it on battery primarily, you'll drain it from the maximum number of cycles. As mad_jew already emphasized, use your laptop on AC whenever possible...
     
  14. Hadley macrumors member

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    Dec 20, 2006
    Location:
    Philadelphia, PA
    #14
    So when i turn my mbp off at the end of the day when i go to bed and it is fully charged, i should unplug it?

    i run off battery power probably once or twice a day, and it never gets below around 60 percent power...is there anything i could be doing to prolong the battery life? its still a rather new computer, but id definitely like to do things right and get hte most out of this battery.
     
  15. mad jew Moderator emeritus

    mad jew

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    #15
    It won't really matter if it's shut down, but leave it plugged in if it's asleep simply so it can use mains power rather than battery power. :)
     
  16. phungy macrumors 68020

    phungy

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    Dec 5, 2006
    Location:
    FL/NY/TX
    #16
    Whew. I have been doing this every night and wasn't sure if it was alright or not. Now I can rest easy at night.
     
  17. roxnadz macrumors regular

    Joined:
    Feb 15, 2006
    #17
    How do you know if you have a defective battery or not?

    When I bought my C2D two weeks ago, I had 5500mAh of battery capacity. Now according to System Profiler, I only have 4500mAh. I've definitely noticed a difference in the amount of time I can use the computer when off mains. At first it was 3 hours, now it's a little over two.

    I'm wondering if I shouldn't pay the Genius Bar a visit...
     
  18. aquajet macrumors 68020

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    VA
    #18
    Have you tried to calibrate your battery recently? If not, I would start with that.
     
  19. roxnadz macrumors regular

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    Feb 15, 2006
    #19
    Yeah, I did a deep discharge following Apple's instructions. When I ran it down, I was at 0% for about 15-20 minutes before the MBP forced itself into sleep. I had the pulsing light for over a day before the light finally went out (and it safe-slept).

    Then I let it charge up until I got the green light on my MagSafe. Unfortunately I'm still at 82% of original capacity. Total available mAh went up by 39 (from 4528 to 4567). Don't get 100% on the charge meter (99%)

    Will try deep discharging it again to see if I can raise it up but I'm wondering if I do have a bad battery.

    Edit: Now System Profiler is saying I have 5033 total available mAh. And that just dropped by 19 mAh in the 20 minutes since I refreshed it. Weird...though, I'm at 66% availability after 1 h of usage.

    Edit 2: And now I'm at 5393 mAh, thirty minutes later. Down to 54%.

    Edit 3: LOL now I'm back down to 5017 mAh, an hour later. Down to 18--no wait, make that 17%. Total usage 2h35, computer estimating 33m till forced sleep.

    Edit 4: And now at the low-battery warning, I'm back up to 5421 mAh with 3h15 of usage, and 9m remaining. I'm gonna let it do another deep discharge again and see if this helps right things. I dunno how Apple got 5h30 out of these things, but it must have been under the gentlest of circumstances. I've been surfing the web and playing music with both my wifi card and my Bluetooth on. Last time I went about 15m at 0% before forced sleep. We'll see how long this one goes. Then I'll let it go into safe sleep (thank god I still have my Rev E 17" Powerbook!)
     
  20. mad jew Moderator emeritus

    mad jew

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    Apr 3, 2004
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    Adelaide, Australia
    #20
    roxnadz, are you saying it's flat after just over three hours? What apps do you have open? Something like a file sharing app can take out a lot of power because it uses so much hard drive time. Five and a half hours isn't a great figure in that it's difficult to replicate. However, you should be past four quite easily unless you're doing something intensive. :)
     
  21. aquajet macrumors 68020

    Joined:
    Feb 12, 2005
    Location:
    VA
    #21

    That is kind of screwy that the reported capacity jumps around.

    You might try resetting the SMC to see if that makes a difference.

    Keep an eye on it in the meantime. If it continues acting strangely, maybe talk to a genius and see what can be done. Perhaps there's something wrong with the battery. I've had similar problems in the past with my battery but lately, it seems to be working okay. Who knows... :rolleyes:

    As a side note, using Airport and Bluetooth will decrease your run time. You definitely won't get the maximum time that Apple claims.
     
  22. vansouza macrumors 68000

    vansouza

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    West Plains, MO USA Earth
    #22
  23. e12a macrumors 68000

    e12a

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    Oct 28, 2006
    #23
    The procedures for calibrating a C2D is different from the old powerbooks. You have to wait 5 hours before turning the computer on again after you let it sleep from a low charge. Just discharge it at night and let it sleep while you do the same until you wake up (at least 5 hours from then).

    from apple support site (remember this is intel-mac specific).
    # Continue to keep your computer turned on until it goes to sleep. Save your work and close all applications when the battery's charge gets low and before the computer goes to sleep.
    # Turn off the computer or allow it to sleep for five hours or longer.
    # Reconnect the power adapter and leave it connected until the battery is fully charged. You may use your computer during this time.

    "Apple does not recommend leaving your portable plugged in all the time. "

    my batter fluctuates between 98 and 99%
     
  24. roxnadz macrumors regular

    Joined:
    Feb 15, 2006
    #24
    But I did let it sleep five hours. In fact, once it forced itself to sleep, I let it sleep for over a day, until it finally safe-slept.

    This last time (about 1am yesterday), I was able to run about 3h25 before the computer forced itself to sleep. I then let it sleep overnight and most of the day (today) and when I got home the sleep light was off, so I'm assuming it safe-slept.

    I'm charging it up again now. I will open it up after I send this and see what my max capacity is now.

    We'll see if these deep discharges fix my problem.
     
  25. e12a macrumors 68000

    e12a

    Joined:
    Oct 28, 2006
    #25
    c2d mbp's batteries usually last 3 hours and maybe a few minutes more on a full charge so your battery is probably okay...the chip on it might not be functioning correctly to report the accurate health though.
     

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