4 Replies Latest reply: Nov 12, 2013 5:04 AM by dwb
LynGeoTech Level 1 Level 1 (0 points)

Can i charge in between calibrations?


That is, If ive completed a calibration, do i use

1. battery power until battery dies

2. do i use a bit of battery for the day and charge to 100% again and keep doing this for a few weeks (everytime i use macbook) until i want to calibrate again?

3.Or do i just keep on AC power whenever i can

MacBook Air
  • stedman1 Level 9 Level 9 (63,455 points)

    1: No

    2: Absolutely no reason to try and charge to a specific percentage.

    3: Yes

  • Zombie Slayer Level 1 Level 1 (40 points)

    The instuctions for calibration I have are as follows:

    a) Fully charge your MacBook.

    b) Once fully charged, leave it plugged in for at least another 2 hours.

    c) Remove the MagSafe power adapter, and use your computer until it reaches around 5% remaining.

    d) Plug in your MacBook and charge it to 100% battery life.

    e) Once fully charged, your battery has been properly calibrated.


    I read that it is good to do this every few months, but not everyone thinks it is good to intentionally deplete the battery's charge. Calibrating seemed to help my MBA get more accurate battery time estimations, but it is up to you.

  • PlotinusVeritas Level 6 Level 6 (14,710 points)

    Your #1 No, NEVER DO THAT.


    As per Apple:

    Portables with built-in batteries

    Current Apple portable computer batteries are pre-calibrated and do not require calibration procedure.



    There is no "calibrating" on your LiPo battery despite many flapping lips about this 'procedure'.


    Keep it plugged in when near a socket so you keep the charging cycles DOWN on your LiPo (lithium polymer) cells / battery.


    *Contrary to some myths out there, there is protection circuitry in your macbook and therefore you cannot 'overcharge' it when plugged in and already fully charged

    You certainly CAN leave your macbook plugged in all the time, take it off charge and drain the battery down to 15 or 20% every couple of weeks or so.


    *However if you dont plan on using it for a few hours, turn it OFF (plugged in or otherwise), ...*you dont want it both always plugged in AND in sleep mode


    LiPo (lithium polymer, same as in your macbook) batteries do not need conditioning. However...


    LiPo batteries do NOT like to be dropped down to 15% or so often,....key word being "often"


    A lot of battery experts call the use of LiPo cells the "80% Rule" ....meaning use 80% of the charge or so,.. then recharge them for longer overall life.


    Never let your Macbook die from power, you can corrupt files that way, and the batteries do not like it.



    The only quantified abuse seen to LiPo cells is instances when  often the cells are repeatedly drained very low.


    *Also, if youre going to store your macbook away for a few weeks or more,... make sure it has at least a 50% or so charge.


    *Cycle count / use/ lifespan is one thing that cant be countered.



    Proper treatment is another thing. Just because LiPo batteries dont need conditioning in general,.. does NOT mean they dont have an ideal use / recharge environment. Anything can be abused even if it doesnt need conditioning.


    Just use and enjoy your new macbook, 


    From Apple on batteries:





    but really all you would keep in mind is --"consider 15-20% is the same as 0% and recharge it"


    and best "tip" is if its near a socket, .....plug it in as long as you can (especially at home) since cycle count on the battery are the "miles that wear out the tires (battery)"




    Important useful info on your Lithium cells as compiled from battery experts:


    Heat increases battery performance but shortens life by a factor of two for every 10°C increase above 25–30°C (18°F above 77–86°F). This is yet another important reason for the cooling of any notebook, not just keeping the processor and GPU cool. Mavericks lower power tasking (app nap) and combined with the cool running Haswell processor both greatly protect battery life on your Macbook now more than ever before.


    Good news: *Mavericks not only increases a single charge cycle for longer battery use off a full charge,… but also prolongs the overall long term life of the LiPo battery in a Macbook by reducing the load conditions the battery experiences from heavy peak-use.


    Counting cycles is not conclusive because a discharge may vary in depth and there are no clearly defined standards of what constitutes a charge cycle on a Lithium Ion battery empirically. Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count.


    The shorter the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine.


    Frequent HIGH depth of discharge rates (draining the battery very low) on a Lithium battery will hasten the lowering of maximum battery capacity.


    Although better performing when warm, lithium polymer batteries live longer when kept cool.


    Lithium cells prefer draining conditions at a steady pace rather than fast pulsed or quick discharges, …this fact is idealized now with the Haswell and Mavericks app-nap low power tasking for battery use.


    App nap:


  • dwb Level 7 Level 7 (21,635 points)

    Apple notebooks with non-removable batteries do not require calibration - this comes directly from an Apple Knowledgebase article. Apple recommends that users do not keep their notebook charging 24/7/365 and suggests that they be used on battery power at least once a month. I have a repeating calendar event so I don't forget. As you use the computer on battery power you will get a warning when the computer is on reserve power. In other words there's not much time left. At that point you should always plug it back in if possible. If you aren't in a location where you can plug it in if you'll be able to plug it in within the next 30 minutes or so, put it to sleep, otherwise shut down. The most damaging thing you can do to your battery is totally discharge it.


    To repeat. Your MBA doesn't need calibration. It should be used on battery power at least once a month. Never totally discharge the battery. Living by these rules my 2009 MBP 's battery health remains over 93%. Not bad for a 4 year old battery, eh?