Authored by:

How to calibrate the battery on your Android phone or tablet

Authored by: Kris Carlon — 1 week ago

Battery problems are among the biggest concerns for smartphone users, which is why we offer many useful tips and tricks for solving battery drain issues. If you notice that your battery performance and duration has decreased, it could be time to consider calibrating your battery. So today we'll explain what battery calibration is, how to know if you need to calibrate your battery and how to do it, with or without root access.

androidpit samsung galaxy s5 review 7
Sometimes you need to recalibrate your battery to get back on track. / © ANDROIDPIT

How do I know if my battery is the problem?

First of all you need to identify why your battery performance has decreased: is it the battery itself or is it the Android system's calibration? We'll move onto calibration in the sections below, but you should check if your battery itself is damaged first. 

If your phone has a removable battery cover, turn of your phone, remove the cover and inspect the battery. Look for bulges, leaks or a bloated battery. You may have see our image below where the Galaxy S6 battery swelled and popped the non-removable back off our S6. On phones without a removable battery, keep an eye out for things like this or a phone that doesn't sit flat on the table anymore.

Galaxy s6 back taking off 3
This is an obvious indicator of a swollen battery. / © ANDROIDPIT

If you're satisfied that the battery itself is not the problem, you can move on to the steps below. If you think your battery might be the problem (even after trying to recalibrate it), we'd advise you to take it to a repair shop for an expert's opinion. If it turns out you need to replace the battery, go with an original or reliable third-party battery. Scrimping on a cheap knock-off battery only leads to more headaches in the long run.

Keep in mind that there are plenty of other things that can cause a battery to malfunction. If your phone doesn't charge, there might be a problem with the port, so check our guide on what to do when a phone won't charge.

If you've just updated the firmware on your phone, battery drain is a common complaint, so you might want to clear the cache partition on your phone. Search the site, we have plenty of guides on how to clear the cache on various devices.

AndroidPIT Nexus 6 wireless charging
It's a good idea to be familiar with what's normal for your battery. / © ANDROIDPIT

What does it mean to calibrate a smartphone?

The Android operating system has a feature called Battery Stats, which keeps track of battery capacity, when it is full or empty. The problem is that it sometimes it become corrupted and starts displaying data that isn’t real, which, for example, causes the phone to turn off before reaching 0 percent. Calibrating your Android battery simply means getting the Android OS to correct this information so it is reflective of your actual battery levels once again.

It's important to understand that you can't actually calibrate the battery: it is, after all, just a cell that stores and discharges. However, lithium-ion batteries do include a printed circuit board (PCB) that serves as a protection switch to stop them from exploding or deep discharging.

Battery DEAD ON fire ANDROIDPIT
Although some batteries do explode, it's a rare occurence. / © ANDROIDPIT

Smartphone battery myths

Lithium-ion batteries don't have a memory so there's not much you need to do to keep them running as they should. The problem lies with how the Android system reads and displays the current capacity of the battery, not the battery itself. 

The same goes for the myth that deleting the batterystats.bin file will magically recalibrate your battery. That file (on most devices anyway) simply stores data about what is using the battery when it is not being charged. It is also reset every time a battery is charged to over 80 percent and then disconnected.

The batterystats.bin file contains the info you see made prettier in the Battery section of your phone: it's the Android system keeping track of your battery's usage, per charge cycle. When we talk about battery calibration, it's the percentage meter that gets out of whack, and that is what we need to fix. 

I'd advise you to read these two background articles on battery technology from the Battery University too:

whatever
If your battery has given up the ghost you should try to recalibrate it. / © ANDROIDPIT

How to calibrate Android device battery without root access

The old 'fully charge and discharge' approach stands as one of the simplest ways to 'recalibrate' your Android battery. We've warned you in the past about low voltage problems in lithium batteries and the negative impacts of fully draining a battery on its lifespan and the same holds true here. But if your phone battery is causing you real problems, it's worth taking the risk.

Method 1

1. Discharge your phone fully until it turns itself off.

2. Turn it on again and let it turn off.

3. Plug your phone into a charger and, without turning it on, let it charge until the on-screen or LED indicator says 100 percent.

4. Unplug your charger.

5. Turn your phone on. The battery indicator will likely not say 100 percent, so plug it in (leave your phone on for this) and continue charging until it says 100 percent on-screen as well.

6. Unplug your phone and restart it. If it doesn't say 100 percent plug the charger back in until it says 100 percent on screen.

7. Repeat this cycle until it says 100 percent (or as close as you think it's going to get) when you start it up without being plugged in.

8. Now, let your battery discharge all the way down to 0 percent and let your phone turn off again.

9. Fully charge the battery one more time without interruption and you should have reset the Android system's battery percentage.

Please remember that it is not recommended to perform this process all the time. Even when your battery is so dead your phone won't even turn on, your battery still has enough reserve charge to avoid system damage. But you don't want to poke the tiger with a stick. Perform this process once every three months at the most. If it is required more often than that you have bigger problems at hand.

Put plainly: fully discharging a battery is bad for it. Trying to overload a battery is also bad for it. The good news is that charging batteries automatically shut off when their safe limit is reached and there's always a little in reserve even if your phone won't start. But again: do this only when really necessary, because it does have a negative impact on battery life.

AndroidPIT Galaxy S6 Ping Pong Root
If your phone has root access you can clear the batterystats.bin file. / © ANDROIDPIT

How to calibrate Android device battery with root access

Even though I'm not convinced that clearing the batterystats.bin file has any meaningful effect on how the Android system reports remaining battery charge, there are those who swear by this method. So in the interests of fairness we've included the process for you here (it is true that different manufacturers use the batterystats.bin file for different things). It's basically the same process as above but with the added step of a root-enabled app.

Method 2

1. Discharge your phone fully until it turns itself off.

2. Turn it on and let it discharge and turn off again.

3. Plug your phone into a charger and, without turning it on, let it charge until the on-screen or LED indicator says 100 percent.

4. Unplug your charger.

5. Turn your phone on. The battery indicator will likely not say 100 percent, so plug it in (leave your phone on) and continue charging until it says 100 percent on the screen as well.

6. Unplug your phone and restart it. If it doesn't say 100 percent, plug the charger back in until it says 100 percent on screen.

7. You want to repeat this cycle until it says 100 percent (or as close as you think it's going to get) when you start it up without being plugged in .

8. Now, install the Battery Calibration app and, before launching it, make sure your battery is at 100 percent again, then restart.

Battery Calibration Install on Google Play

9. Immediately launch the app and recalibrate your battery.

10. Once you've calibrated your battery, discharge it all the way down to 0 percent and let your phone turn off again.

11. Fully charge the battery one more time without interruption and you should have reset the Android system's battery percentage.

That's it. Have you tried any of these methods? Do you know an alternate way to fix battery problems? Let us know in the comments.

Kris Carlon comes to the AndroidPIT Editorial Team via a lengthy period spent traveling and relying on technology to keep him in touch with the outside world. He joined the Android community while resurfacing in civilization back in 2010 and has never looked back, using technology to replace his actual presence in other people's lives ever since. He can usually be found juggling three phones at once and poring over G+ posts, Reddit and RSS feeds.

19 comments

Write new comment:
  • Junaid Qureshi 6 days ago Link to comment

    This trick really help this helped me to recalibrate my s4
    After trying new roms and upgrading to 5.0.1 and downgrading to 4.4.2 my battery didnt last long much than after I got expose module which prevent force shutdown after battery low and I notice that my device work more than 30 min in 0% battery, than I used this trick to recalibrate it back

    Thanks kris carlon u saved my few bucks of new battery

  • Bill Brown 6 days ago Link to comment

    There are battery calibration apps that don't require full discharge, do you not recommend using those?

  • Zion B 1 week ago Link to comment

    This is very useful information. But the problem that I'm having with my S3 besides the battery drainage after the 4.3 update is that, my phone is not charging to 100%. What it does is charges between 95-98%. And if I leave it to charge longer,the percentage starts dropping. Any idea on what I can do to solve this problem would be greatly appreciated

  • g454572 5 months ago Link to comment

    Americans have serious problems with SI units...
    The use of "milliamps" should be sanctioned. mA is a current! it has absolutely nothing to do with capacity! mAh is a charge, in this case it denotes the maximum charge that the battery can hold aka capacity. Integrating a current of x mA over one hour gives you the charge in mAh.

  • Odeta D 5 months ago Link to comment

    üyuuyhgf

  • TiHo 8 months ago Link to comment

    Well my phone will say its charging.. It'll say 20%then it'll say 3%...I need help!

  • Vinnie 9 months ago Link to comment

    There is some useful information in this article.
    However I have to say that Method 2 under "How to calibrate Android device battery without root access" doesn't make any sense... The app tells you what's the instantaneous current in mA and not what's the current capacity of the battery (mAH). There is no way to understand how charged is your battery (other than a percentage based on the batterystats file) by using the app...

    Also the video posted for Method 1 under "How to calibrate Android device battery with root access" is private...

  • Lloyd Abando 9 months ago Link to comment

    When do I knew when my battery is calibrated?

  • Ted 9 months ago Link to comment

    Your instructions are clear as mud and the CurrentWiget is not working on my S3.

    • ofbarea 8 months ago Link to comment

      Works fine with my S3 running CyanogenMod 11 M12. Try rooting your phone, it should work.

  • Zack Samaco 10 months ago Link to comment

    Hi what do you mean when you say "do not load until the smartphone turns itself off after reaching a 0% battery level." does it mean that you have to wait until it goes to 0% without doing anystuff with your phone or is it ok to use your phone while waiting for it to go down to 0%?

    • Scott Adam Gordon
      • Admin
      • Staff
      10 months ago Link to comment

      Ahhh yeah that could be a little clearer. But yes, it is okay to use your phone in this time. If you want the battery to run down even faster, turn your screen brightness to 100% while your are using it.

  • David Apr 17, 2014 Link to comment

    hi guys love all the help ur giving. question ....ive heard from so many people telling me that leaving ur fone charged all day and nite is bad. Also that its better to let the fone drain a bit ..? thoughts?

    • Kat Hervera 11 months ago Link to comment

      to old batteries it applies. but on your smartphone battery it doesn't. just apply the 40/80 rule when charging your gadgets. also remember to keep it cool. ave. batt life span is 3-5yrs. an ave heat of 32deg farenheit decrease batt life up to 6% of max capacity per year.

      • Mat N. 1 month ago Link to comment

        Umm...... Just curious, what the hell is the "40/80 rule?"

      • Kurama Eclair 2 weeks ago Link to comment

        To keep your battery charging level in between 40-80%. Hence, not filling it up to 100% every time. it increases the battery life

  • Amat Mulisha Apr 16, 2014 Link to comment

    does one of this method are harmful to my phone if my battery not having any problem?