iPhone 3G Calibrating

Discussion in 'iPhone' started by yourdream, Jan 21, 2009.

  1. yourdream macrumors regular

    Aug 16, 2008
    So I've been using the phone for several months now and have never calibrated the battery on it. I find the battery actually quite weak, but I'm not sure if it is just the battery indicator being inaccurate. Should I calibrate the battery? If so, how do I do it? I'm assuming to do this every few months, which will not harm the battery right? I know how to do it for my aluminum MacBook but not for my phone.
  2. davyreins macrumors 6502

    Jul 10, 2008
    Ann Arbor
    After a full charge discharge it fully. Then, charge it fully again. Some people think this is necessary, other sdon't. I usually calibrate my batteries for my laptop, ipod, iPhone, etc every once and a while.
  3. Resist macrumors 68030

    Jan 15, 2008
    If these were Metal Cad batteries then I would say do this but they are Lithium Ion and don't have a memory, so this does nothing for them.
  4. yourdream thread starter macrumors regular

    Aug 16, 2008
    All right, so I basically just charge the phone fully and drain it until it is 0%, and then charge it again, right? This won't harm the battery in the phone, right?
  5. Rayfire macrumors 68030


    Aug 25, 2008
    Here you go.
  6. tylertech macrumors regular

    Oct 24, 2008
    It won't harm it, Apple actually encourages it!
  7. Dr. Cabrera macrumors 65816

    Aug 25, 2008
    Los Angeles
    calibration will net you ZERO battery life

    all the calibration does is... calibrate the % remaining

    let me see if I can explain

    If you have a battery that for some reason is not calibrated, it might say that you have 70% of battery life remaining when you actually have 67%.

    you don't gain any extra battery life, but it will be more accurate
  8. pilotkid macrumors 6502a

    Aug 22, 2006
    Chandler, AZ/Chicago, IL
    I have tried draining my iphone fully to calibrate it but then I let it sit and in like a hour if I try to turn it on,(after it has automatically turned itself off because it had no battery left)it will actually turn back on for a few min's. My question is, do I need to keep trying to turn it on until it absolutely wont turn on anymore? Or once it just goes dead the first time can I just plug it in and let it fully charge? And when it does run out do you have to let it sit for a few hours while its totally drained and then when you charge it let it sit for a few hours after its fully charged with the charger still plugged in?:confused:
  9. Trebuin macrumors 65816


    Jun 3, 2008
    Central Cali
    A while ago, during the world of laptop batteries, I was told that it was bad to fully discharge lithium batteries. Something about how they were designed made them die quicker (obviously one discharge won't matter here) and they never gain their full charge back again. I've seen this only once, though.

    Here's why you discharge to calibrate:
    Have you drained a battery dead, then left the device off, came back a few hours later and found it had just a little more life? Everyone should have seen this at least once. What happens is that battery is a multi-cell, each cell does not drain equally and eventually one finally drains completely and the device then turns off. During this period over a hour, the rest of the batteries that hold a charge equalize with that one battery, essentially recharging it. This also creates a crystal buildup and is essentially a bad method of charging.

    Now, if you drain the battery to zero, the crystals will build only once and won't occur on this scale again, this is calibration. If you start wall charging too soon or charge before the battery is dead (only before calibration), the battery will build crystals, but it won't build them were they will stop. The battery loses a little bit of life, but is still open to calibration.

    Here's something to know: if the battery is left dead too long (days to months depending on the battery) it will permanently die. If accidentally or intentionally left grounded to keep it dead (eg, a manual switch flashlight left on) thinking that would be the best calibration, all the cells will eventually discharge, but the crystal buildup will be so bad that the battery can literally explode (leak their guts) and I've seen this...I've ruined a bose aviation noise canceling headset that way.

    Even though the crystals can be built correctly, the battery is eventually going to die because either we can't completely stop the cross charge or the catalyst fails.

    Finally, single cell batteries shouldn't have this issue and last longer. Lithium I heard did not build these crystals, which is why I was told you shouldn't calibrate them. I don't know if that is still true. I don't know if these companies researched this or not. Try google.
  10. firewood macrumors 604

    Jul 29, 2003
    Silicon Valley
    It does nothing for the battery (in fact it wears it out by 1 full cycle), but does do something for the battery calibration (e.g. if poorly calibrated, the device might shut down early or say the battery is empty, when in reality the battery still has an hour of remaining juice.)

    Some say do this once a month, which sounds like overkill (and 12 extra wear cycles). I do it maybe once a year, or when the battery life seems to be changing noticeably.

  11. yourdream thread starter macrumors regular

    Aug 16, 2008
    So If I fully charged my phone and then drained it a little over half and then charged it again a bit because I needed to get an application from the iTunes store, can I then continue to drain until 0% and then fully charge it again? Will the calibration work that way? Or will it harm my battery if I calibrated it that way? Maybe I should just charge it back to full and then drain it to 0% and then charge it to full again for the calibration to successfully work without harming the battery?
  12. TheSpaz macrumors 604


    Jun 20, 2005
    By the way... we're not calibrating the battery. We're calibrating the battery status icon so that it will be in sync with the battery to show accurate usage. That's the reason we drain our lithium-ion batteries. You should only have to do it every once in a while.

    Also, lithium-ion batteries like to be charged often.

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