Battery problems with 2012 Macbook Air

Discussion in 'MacBook Air' started by Blackened Apple, Jan 25, 2016.

  1. Blackened Apple macrumors regular

    Jun 15, 2012
    Hey everyone, I've been having problems with my battery for like a year and a half, capacity suddenly dropped immensely, I'm now down to 23.3% of design capacity, despite only 345 load cycles. When not charging, the battery depletes very quickly, and often shuts down without notice, around the 30-70% battery remaining. I've tried resetting the SMC from time to time, and nothing improves the situation. Should I just bite the bullet and replace the battery? The strangest thing is that one of my friends who bought a MBA around the same time has exactly the same problems.
  2. JTToft macrumors 68040

    Apr 27, 2010
    Aarhus, Denmark
    - Sounds that way. Apple charges $129 for it.

    If you haven't, charge the machine to 100% as well as you can, let it sit there for a while. Disconnect the charger and keep using the machine until it turns off from a lack of power. Reconnect the cable and charge to 100 %.
    If nothing else, it might fix the incorrect charge percentage you're seeing.
  3. julianps macrumors member


    Aug 6, 2006
    Wales, UK
    The theory is 1,000 cycles (from full, down to when you get the warning of less than 5%) before the full charge capacity is 80% of theoretical maximum capacity. If you charge up overnight and run to flat during the day Apple suggests you'll get 1,000 days out of battery (i.e. one complete Applecare lifespan).

    There's some technical stuff about heat and expansion and external cracking and how they combine to diminish lithium ion batteries lifespan, but the main principle is "be nice to them".

    So if you plug in, run it up to 90%, unplug and run it to 35% then plug it in again and only sporadically run to zero and only sometimes to 100% you'll never see that performance level because you're beating the battery to death. And once the maximum is less than 80% of the original max you're heading towards replacement.

    Check this easily by making sure the battery meter is showing in your top toolbar, then and holding down the Option key, click the battery meter. What does it say for Condition: (options other than Normal differ by OS version)? Anything other than Normal means its on it's way out.

Share This Page