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Android phone turns off at 40% battery (FIX)

battery icon featured

There are many opposing opinions in the Android community but one that’s not controversial at all concerns non-removable batteries. Everyone aches for good old removable batteries. Now, there are some downsides and the fact that industry standards changed, but the matter of fact is that batteries are the first piece of hardware that will let you down. In many ways. Users report that the Android phone turns off at 40% battery instead of 1%, as we are used to.

Learn more about possible reasons for this occurrence and how to fix it below.

Why does my phone gets switched off even though the charge is 40%?

There are multiple reasons why your phone shut down at 40% battery instead of 1% (we never see zero). The faulty battery is the first one. The second possibility concerns temperatures, and the third one is battery calibration.

Check the steps below to learn how to tackle this head-on.

1. Overheating or cold weather

The thing with batteries is that they don’t do well with extreme temperatures. Whether it’s super hot or cold, the wear and tear of Lithium-ion batteries will increase. The capacity will drop over time but, if the device is exposed to extreme temperatures, the aging process will speed up, the battery’s internal resistance will drop, and random shutdowns might occur.

So, making sure that your device is not used under those circumstances for a prolonged period of time is a good way to retain the battery’s longevity and avoid issues like this.

The ways to do it are obvious but often neglected. Here are some tips for you:

  • Don’t use your device while charging. Particularly, don’t game on your Android while it’s charging.
  • Don’t keep your device exposed to the sun and don’t keep it close to artificial heating sources for long. The same goes for freezing temperatures.
  • Use the original or supported charging bricks. USB cables are also important but to a lesser extent.
  • Lower the brightness if you don’t need your display to be extremely bright. The max brightness is for when you are outdoors under direct sunlight.
  • Remove the protective casing while charging. If your device and charging brick are hot on touch, power off the device and let it be for some time. Only once it cools down a bit, continue with charging.

If your Android phone still turns off at 40%, make sure to re-calibrate the battery by following the instructions we provided below.

2. Re-calibrate the battery

We already wrote about this in more than a few instances. Batteries are often not the cause of the problem but the actual device readings come as false. So, your device actually turns off when the battery reaches 0% instead of 40%. It’s just that you see the wrong percentage at the top of the screen.

We explained how to re-calibrate the battery and everything else related to the procedure. On the other hand, if you want to get straight to business, follow these steps to recalibrate the battery on your Android:

  1. Discharge your phone fully until the phone turns off.
  2. Turn it on again and wait until it turns off.
  3. Plug your phone into a wall socket, without turning it on, and charge it until the on-screen indicator says ”100 percent”.
  4. Unplug your device.
  5. Turn your device on. If the battery percentage is not at 100%, plug the charger again until the UI shows that the battery is 100% full.
  6. Unplug your phone and restart it. If the battery is still not at 100%, plug in the charger and charge it until the battery is 100% full.
  7. If necessary, repeat this cycle until it says 100 percent.
  8. Now, discharge your battery until the phone turns off by itself.
  9. Fully charge the battery one more time. Don’t turn on the device or disrupt charging.

This should fix the readings. If it doesn’t help and your Android phone turns off at 40% again, repeat the discharge/full-charge cycle until the readings are punctual.

3. Check the charger

We already mentioned charger brick but we didn’t mention the benefits of slower charging over fast or ultra-fast charging. These days, there are Android devices that come with 65W or even 120W charging bricks that will fill up enormous batteries in 30 minutes. No matter how much this can be convenient when you are in a rush, battery life will suffer over time. Don’t get us wrong, it’s still a million times better than not getting a charger at all.

So, this is more of a tip than a solution for your problem, but consider using standard chargers when charging overnight or use software to change the charging mode to a slower one. If possible, of course. Hopefully,

4. Reset your device to the factory settings

Finally, we are unsure about claims that this is a software issue that came with a firmware update. We are more inclined to believe that you, in fact, have a faulty battery that needs replacing. However, there is a thing called fuel gauge system calibration (it’s a mouthful alright) that is, plainly said, a way for software to manipulate voltage based on real-life battery performance. And this, like all other system processes, depends on the firmware updates.

If an update breaks it (a really rare occurrence), you might need to reset your device to factory settings. Have in mind that some users even went a step further and rolled back to an older system version. The issue continued for many of them. So, it’s a tricky situation but, if you have some time to spare, the factory reset still sounds like a viable option.

Here’s how to reset your Android to factory settings:

  1. Back up everything. Use either cloud drives or transfer all data to an SD card or externally, to your PC.
  2. Open Settings.
  3. Choose System.
  4. Select Reset options.
  5. Tap Erase all (factory reset).reset device to factory settings android 11 2
  6. Tap Erase all.

And, on that note, we can conclude this article. Thank you for reading and feel free to tell us if these solutions helped you address the problem. Also, post your questions and suggestions so we can add them to the list of solutions. The comments section is just below.

Editor’s note: This article was initially published in November 2021. We made sure to revamp it for freshness and accuracy.

Picture of Aleksandar Ognjanovic

Aleksandar Ognjanovic

Managing editor at Mobile Internist. @lemmingspain My fascination with mobile technology, particularly Android and iOS, began years ago and continues today. I'm captivated by the constant evolution in the smartphone industry and its impact on our daily lives, always anticipating the next big innovation. That’s the main reason why I found myself writing instructive content on the subject for users who are not as familiar with all the bells and whistles.
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