Calibrate Your Phone’s Battery To Get An Accurate Reading On How Much Juice Is Left

Calibrate Your Phone’s Battery To Get An Accurate Reading On How Much Juice Is Left

If your smartphone’s battery reading doesn’t match up with your usage pattern, it might be time to calibrate it. Here’s what you have to do.

The folks at How-To-Geek detailed a way of calibrating your phone’s battery to get a more accurate picture of how much juice you still have left:

  • Let your phone drain completely until it shuts down automatically and won’t turn back on.
  • Put your phone on charge without turning it on. Leave it until it’s fully charged.
  • Turn your phone back on and confirm that the battery bar shows that it’s 100% charged.
  • Unplug your phone. The battery should now be calibrated.

It’s not an exact science and there are other ways of calibrating your phone battery, but the process above is pretty easy to follow.

Head over to How-To-Geek to find out more about battery calibration and how, despite what others have said, the process doesn’t make your phone battery last longer.



  • The awkward moment when posts the following on their article (

    Smartphones today have lithium-ion batteries, which don’t suffer from the memory problems of older nickel cadmium and nickel-metal hydride batteries. Similarly, lithium-ion batteries count charges differently than older batteries, so you don’t need to worry about discharging it completely. Here’s how Apple explains it, and while they reference their batteries, the rules apply to any lithium-ion battery.

    Charge your Apple lithium-ion battery whenever you want. There’s no need to let it discharge 100% before recharging. Apple lithium-ion batteries work in charge cycles. You complete one charge cycle when you’ve used (discharged) an amount that equals 100% of your battery’s capacity — but not necessarily all from one charge. For instance, you might use 75% of your battery’s capacity one day, then recharge it fully overnight. If you use 25% the next day, you will have discharged a total of 100%, and the two days will add up to one charge cycle. It could take several days to complete a cycle. The capacity of any type of battery will diminish after a certain amount of recharging. With lithium-ion batteries, the capacity diminishes slightly with each complete charge cycle. Apple lithium-ion batteries are designed to hold at least 80% of their original capacity for a high number of charge cycles, which varies depending on the product.

    • The awkward moment when someone doesn’t read the whole article that they link…

      “Discharging to 0% once a month helps the operating system calibrate the full life cycle of the battery so it knows exactly how much it has diminished over time.

      “… These ‘smart batteries’ supposedly reduce the need to calibrate, though it’s still recommended when your battery behaves oddly. If you see the battery percentage on your phone jump around a lot (like you could have sworn it was fully charged, and now it’s at 20%,) it’s time to calibrate it.”

      What you quoted in your comment doesn’t relate to calibration…

      • The awkward moment when you yourself don’t read the whole article but still rebut my comment:

        It’s actually bad for lithium-ion batteries to be regularly drained all the way to 0%. That counts as a full charge cycle, which in turn decreases the battery’s total life.

        • I never mention anything in the article about whether it’s good or bad for battery life. This article is about battery calibration only. The article also never makes any recommendation about doing it regularly.

          Look, thanks for pointing out that it could be bad for the battery if you do it regularly? But this article only provides brief instructions on how to calibrate your battery when you need to do it.


  • Great! Except iOS devices cannot be charged whilst turned off! They turn on as soon as connected to a charger!

  • Heya,

    That’s fine. It’s just you shouldn’t do a full power on when you’re trying to do the calibration.


  • Just use AccuBattery on Android phones. It is excellent and explains the science behind the battery charging.
    Short version : Only charge your phone to 80% to minimize the amount lost over time.
    Charging to 100% will lose around 10% capacity over a year

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