rMBP Charge & Battery Use

Discussion in 'MacBook Pro' started by macNewbie02, Jul 28, 2012.

  1. macNewbie02 macrumors regular

    Mar 4, 2012

    After one week of using my rMBP I would like to know how do you guys charge your battery.

    Since I got my rMBP last week I have been using the battery until it gets to 10% and then plug in the charger until it gets to 100% then I unplug it and do the same again.

    Is that the recommended usage of the battery and charger?

    Most of the time I use the computer at a desk where I can work when ever I want with charger plugged in - but I'm not sure if it's good or bad for the battery.

  2. miles01110 macrumors Core


    Jul 24, 2006
    The Ivory Tower (I'm not coming down)
    The recommended way to use your battery and charger is "however you want to." Batteries can be replaced. Trying to extend its life or preserve it is folly.
  3. GGJstudios macrumors Westmere


    May 16, 2008
    Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug at any time, regardless of the charged percentage. Just make sure you don't run on AC power all the time, as your battery needs to be used regularly to stay healthy. This should answer most, if not all, of your battery/charging questions:
  4. Dangerous Theory macrumors 68000

    Jul 28, 2011
    You aren't doing the battery a service by constantly running it down. For the most of the time, if it can stay plugged in, it's worth doing.
  5. leman macrumors G3

    Oct 14, 2008
    This is wrong. The battery needs to get its exercise, which means that it must be discharged/recharged regularly. GGJstudios already said everything there is to say on the matter.
  6. Dangerous Theory macrumors 68000

    Jul 28, 2011
    It needs to be cycled occasionally - even monthly will suffice - but constantly discharging (especially to low levels like 10%) and recharging is not good for it.
  7. underthehanie macrumors newbie

    Apr 2, 2012
    OMG so many varying answers. .

    Just try to keep your mac charged whenever possible. This reduces the charge cycle, every battery has a certain charge. And for our macs lithium ion battery, it can hold up to 1000 cycles. The faster u reach that 1000 cycle, the faster your battery life deteriorates. However, that doesnt mean you charge your mac forever. At least once a month, u have to discharge it fully. This ensures that the ions in the battery are replaced with new ones. Not only that, it also re-calibrates your battery level.

    For the once a month discharge, I guess should not be a problem for any one of us since, we got a laptop and not a desktop for a reason.
  8. ahdickter macrumors 6502

    Jun 12, 2011
    Pittsburgh, Pennsylvania
    Because he has the rMBP, replacing the battery is much more difficult. I can see why he wants to try and make his battery last as much as possible.
  9. tau101 macrumors member

    Jul 28, 2012
    I learned the hard way with my last macbook the impact on the lifespan of your battery of leaving it plugged into the mains for extended periods (18 months in my case). After 3 years and less than 200 cycles the battery health is at 40% of design capacity.

    I intend to ensure I run the battery on my new rMBP down to 0% at least once weekly or fortnightly, and calibrate the battery once a month or so. This should only add annually somewhere between 26 and 52 cycles to a battery designed to degrade to 80% health after 1000 cycles, but the regularity of battery use is key.
  10. AZREOSpecialist macrumors 68020


    Mar 15, 2009
    One thing I can tell you for sure - don't listen to anyone here. Listen to Apple:


    Lots of great information on this page which validates some of the advice given here but contradicts others. For instance, Apple says to never keep the laptop plugged in all the time because you need to keep the electrons in the battery moving occasionally. Apple suggests that the perfect use for a laptop, and maximum battery life, is running on battery during the day and charging in the evening. Apple also says that if you are using your laptop infrequently, i.e., you use a desktop most of the time and a laptop only occasionally, that in this situation you run down and recharge your battery once per month. This only applies if you keep your MBP plugged into the wall most days and don't use it regularly "on the go".

    Remember that Apple rates all of its laptop batteries to have a 5-year lifespan IF you follow their guidelines. By then, you will probably be ready to replace your RMBP anyway. This is why the criticism of having a built-in battery is nonsense in my book. Apple is shipping millions upon millions of devices with built-in, non-replaceable batteries in iPods, iPhones and iPads. Apple has a lot of experience here.

    Check out the Apple page and incorporate their suggestions into your routine. Again, don't take anyone's advice here unless they are an engineer familiar with battery technologies or have actually designed batteries themselves. Everyone else is only repeating something they read or heard, or are stating a personal experience. No offense to anyone here, but I would rather take my battery tips from Apple. After all, they are the ones who designed the battery.
  11. GGJstudios macrumors Westmere


    May 16, 2008
    Some prefer to make up their own procedure, but if you want the facts according to Apple, read the Battery FAQ and the supporting links.
    Bad advice. Read the FAQ.
    False. Read WHAT IS A CYCLE? in the FAQ.
    That's also false. Charging doesn't replace ions and it doesn't re-calibrate the battery. The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries in older Apple notebooks.
    You do not need to calibrate the battery, and doing so puts unnecessary cycles on it. Read above.
  12. 725032 Guest


    Aug 5, 2012
  13. Xerotech macrumors 6502

    Jul 22, 2011
    It's not a Dell. The battery doesn't get completely screwed when plugged in. However, since it's a laptop you should be moving it around and stuff? Haha.

    Use it as you would normally use a laptop.
  14. tau101 macrumors member

    Jul 28, 2012
    Thanks for this.
  15. Dangerous Theory macrumors 68000

    Jul 28, 2011
    I wouldn't discharge to 0% ever. I would avoid sub 10% as much as possible to be honest. The deeper the discharge, the greater the rate the LiIon batteries degrade capacity.

    LiIon rate of capacity loss is also proportional to it's temperature. Keep batteries as low temp as possible.

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