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Studying the Slow Decay of a Laptop Battery For an Entire Year

First time accepted submitter jradavenport writes "I've been keeping a log of the health of my MacBook Air battery for the past year, taking samples every minute I use the computer (152,411 readings so far!). This has allowed me to study both my own computing/work habits, but also the fascinating rapid decay of battery capacity. Comparing it to my previous 2009 MacBook Pro, the battery in this 2012 Air is degrading much faster."

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  1. On Apple you don't need to remove the battery!!! by tibit · · Score: 4, Interesting

    It shows that you don't know the details of Apple's power delivery architecture. Magsafe-equipped Apple laptops are intentionally crippled in that the charger is artificially disabled if you use an unauthorized one. There's a chip in the magsafe plug that connects to the middle pin and is interrogated by the system management on the mainboard. If the interrogation fails, you can still use the power source, but the charger is disabled.

    All it takes not to charge the battery is to cover the middle magsafe pin. I've done it by keeping in use one charger with a bad magsafe plug where the chip had died. Died how? Ah, exposure to the saliva of a 1 year old, he liked to lick those plugs, they admittedly taste "funny" since they are energized :)

    That way you have the best of both worlds: you don't lose your work if the magsafe plug is kicked loose, and you don't charge the battery if you don't want to. Win-Win.

    --
    A successful API design takes a mixture of software design and pedagogy.