Charging too much kill the battery?

Discussion in 'MacBook Air' started by kat.hayes, Nov 20, 2013.

  1. kat.hayes macrumors 6502a

    Oct 10, 2011
    I am on the go alot and do not want to carry a charger with me. I know the MBA has good battery life, though to ensure it always has a good charge, is it a bad idea to connect to a charger when it does not need to be? When I'm home, I will usually connect my Macbook Pro to the charger even when it is at 90%

    Does this kill the battery quicker than it would otherwise?

  2. 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 any time you need to, regardless of the charged percentage, and you never need to completely drain your battery. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.
    The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
  3. Jonathanchasr macrumors newbie

    Nov 18, 2013
    Battery Answer

    You can charge your battery at any percent, your batteries health is basically measured by charge cycles. A full cycle is a charge from 0% to 100%, more full cycles you use the quickly you will kill your battery so charge at higher percentages, you can use the command
    ioreg -w0 -l | grep Capacity
    in terminal to check your batteries health or mAh as well as charge cycles.
  4. GGJstudios macrumors Westmere


    May 16, 2008
    For a more complete definition, read the WHAT IS A CYCLE? section of the Battery FAQ link, posted earlier. Also, some users may not be comfortable using Terminal to get battery information. If that's the case, you can find the same information in System Profiler, or with 3rd party apps like iStat Menus, iStat Pro or coconutBattery, as explained in the Battery FAQ.
  5. teffers macrumors regular

    Jun 23, 2013
    United Kingdom
    I understood that the battery reaches 100%, then it discharges back down to 95%, it then it starts charging again. Hence why the stock battery info reports up to 5% less than the actual so users don't continually see it dropping from 100% whilst on charge - leading to fear, uncertainty and doubt regarding the health of their shiny shiny device :D
  6. GGJstudios macrumors Westmere


    May 16, 2008
    That is false. Once fully charged, it stops charging completely and runs on AC power as long as it's plugged in. There is no such trickle charge mode.
    This is also false. The Apple notebook charging system is designed to avoid such short discharges/recharges. That's why if you plug in when the battery is already 93-99% charged, it will not charge. You must first run on battery and drain to the low 90s or lower before it will charge again.

    Read the Apple Notebook Battery FAQ for accurate information on batteries and charging.

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