Is the battery health indicator accurate?

Discussion in 'MacBook Pro' started by caspersoong, Nov 23, 2012.

  1. caspersoong macrumors 6502a

    Feb 27, 2011
    I have a MBP 13-inch Late 2011, OS X 10.8.2. iStatMenus, CoconutBattery all have a battery health indicator stating the current capacity. But is it accurate? Does it merely count the health based on the number of cycles or does it actually gauge the health (and true capacity) of the battery? I understand it asks the battery driver for the capacity of the battery. There are other reasons other than the number of cycles a battery undergoes which can cause it to deteriorate, including heat. I live in a hot country, and I thus wonder whether the battery health it states is accurate. I say this because I now only get about 5 hours of runtime not doing much with my MacBook Pro, and sometimes the projected battery life can dip to just above one hour. According to Anandtech, even downloading stuff, surfing the web and playing a video simultaneously still allows the battery to last 3.6 hours. How is this possible? Thank you!
  2. T5BRICK macrumors 604


    Aug 3, 2006
    Battery life will vary depending on what you're doing. I can get 4 or 5 hours of battery life out of my mid 2009 MBP for very light usage, but if I'm doing anything processor intensive, it'll die in an hour or two. The health indicator will fluctuate up and down sometimes.

    Don't worry about your battery, just use your computer and enjoy it. Make sure you run off of the battery about once a month to keep it in good condition.
  3. gorskiegangsta macrumors 65816


    Mar 13, 2011
    Brooklyn, NY
    The "health" indicators determine the current overall capacity of the battery (in mAh) and compare it to maximum designed battery capacity. I don't think the number of loadcycles matters very much as I have nearly 500 and the battery health still hovers around 90%.

    As for battery life, that can depend on many factors, including the version of OS X you're using. I was getting 7hrs on 10.7.4 Lion doing basic browsing/word processing whereas I am only getting about 4hrs doing the same tasks in ML. Right now, as I type this, with 51% charge remaining, iStat Pro tells me I have 2hrs 33mins left. So, it all depends.

    Attached Files:

  4. caspersoong thread starter macrumors 6502a

    Feb 27, 2011
    Thanks! I was worried that this was due to permanent damage to my laptop's battery. Now, only if Apple was a bit more caring they could just improve battery life via a software update. Great and useful answer.

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