How to Calibrate the Phone’s Battery After Flashing a new ROM or Kernel

If you are like me, changing roms very often, you will find yourself calibrating your phone’s battery very often. I remember the first rom I flashed back when I had my Sprint Hero, battery life was terrible after flashing it, and since I was a n00b back then, I did not know that I had to calibrate my phone’s battery. After some research, I was able to find out that I needed to calibrate the battery and the how-to thread.

Our smart phones have Li-Ion batteries, they do not have a memory, therefore by saying “calibrating battery” we mean calibrating how Android reads the battery. When flashing a new ROM or Kernel, Android may read the battery as full, when in reality is not full and by calibrating the battery, we make sure Android reads the battery properly. This being said, while reading the XDA Forums I stumbled upon a good write out of three methods on how to calibrate our phones batteries.

You have to go into Recovery Mode First

  1. Power off phone or pull battery and replace.
  2. Hold all three of these buttons down: Vol-Down, Camera button (lower left as you look at the phone) and Power on button. (This combination is for the Epic 4G, other phones have other key combinations)
  3. You will see a small graphical menu come up. Most of us are using Clockwork, so I will focus on that – it will be a green menu.

Method 1 – The Drain Way

  1. Drain it down until fully dead.
  2. Charge normally to full.
  3. Reboot to Clockwork recovery and wipe battery stats (under advanced, on second page), reboot phone.
  4. Turn everything on, flashlight, Bluetooth, Wi-Fi, Pandora, the whole nine, to quickly drain it completely dead.
  5. Charge normally to full.

Method 2 – The Powered Off Charge way

  1. Charge your phone 100% while it’s on.
  2. Unplug it from the charger, power off, then charge it up to 100% with it in a powered off state.
  3. Unplug charger from phone. Power it on, and then charge it to 100% while the phone is on.
  4. Unplug the charger and then reboot into Clockwork, go to advanced and clear the battery stats.
  5. Power on, charge to full, and then enjoy.

Method 3 – Mr. Miagi Charge way

Maybe we can call it the Mr. Miagi Charge way….aka Power On, Power Off, Charge On, Charge Off way lol

(the parentheses are the state of the phone)

  1. Start with the phone powered on.
  2. (Phone on) Charge battery until the LED turns blue
  3. (Phone on) Unplug the phone from the charger, wait until the LED turns off
  4. Power off the phone.
  5. (Phone off) Plug the adapter into the phone, charge it up until the LED turns blue
  6. (Phone off) Unplug, wait until the LED turns off
  7. Power the phone on.
  8. Wait until the phone is booted back up all the way, and then power it off again
  9. (Phone off) Plug the adapter into the phone, charge it up until the LED turns blue.
  10. Boot the phone into recovery mode
  11. Go to Advanced, and then choose Wipe Battery Stats.
  12. Power the phone on and use normally.

NOTE: I did not come up with these methods, just reposting it from the XDA Forums: Calibrate Battery thread – This is how you do it!


Esau Silva
Software Engineer at Region One ESC
Full Stack Software Engineer working with Microsoft technologies, ReactJS is awesome and avid Brazilian Jiu-Jitsu practitioner
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7 thoughts on “How to Calibrate the Phone’s Battery After Flashing a new ROM or Kernel

  1. Esau Silva says:

    New Post: How to Calibrate the Phone's Battery After Flashing a new ROM or K… #Android #CalibrateBattery #BatteryLife

  2. Daniel Dourado says:

    Thank you very much!

  3. Walid says:

    2nd method resolved me the problem. ! thanks a lot

    Motorola Defy (MB525)
    Cyanogen Mod 7.1

  4. Mihai says:

    It has been proved that wiping battery stats doesn’t do anything. A Google engineer has come forth and said that each time you reboot a Android phone, battery.bin is re-written and that it just holds some information about what drained the battery. Sadly, all this is just Placebo.

  5. Irteeza says:

    I hope it will work on my HTC desire 500

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