Have you noticed that Xiaomi suddenly turns off at 20 to 30 percent charge, when it used to run to 1 percent? Or after updating MIUI, the battery discharges in a few hours, even though it used to last a day? The reason may lie in the desynchronization of the power controller — when the actual battery charge does not match the data that the system shows. In 80 percent of cases, the calibration of the battery solves the problem, but you need to do it correctly, otherwise you risk aggravating the situation.
In this article, we’ll discuss what calibration really is (spoiler: it’s not a magic button that will bring back battery volume) when it really helps and when it’s useless. We’ll describe in detail 3 working methods for Xiaomi, Redmi and POCO smartphones – from standard reset via MIUI to manually using ADB. We’ll also warn about critical mistakes that users make most often (for example, using apps for “quick calibration” from Play Market).
What is a battery calibration and why you need it
Calibration is synchronizing the charge controller data with the actual state of the battery. Every Xiaomi battery has a Battery Management System (BMS) that tracks charge levels, temperature and discharge cycles. Over time, due to firmware failures, deep discharges or improper charging, this data “disperses”: the phone shows 50%, but in fact, the charge is 30% or vice versa.
Signs that calibration is needed:
- 🔋 The smartphone turns off at 15-30% charge, although previously worked up to 1-5%.
- 📉 After updating MIUI The battery discharges 2-3 times faster.
- ⚡ The charge is “stuck” at the same level (for example, 80%) and does not move for an hour or two.
- 🔄 Charge percentage jumps: 40%, then 1% after rebooting.
Important: calibration does not restore the capacity of the worn-out battery! If the battery is physically degraded (for example, after 500+ charging cycles), the procedure will only temporarily correct the percentage display, but will not return the previous operating time.
⚠️ Warning: Don't confuse calibration with battery "training"! full discharge/charging method (0–100%) It is only relevant for Ni-MH batteries, and Xiaomi is Li-Po/Li-Ion. For them, deep discharges are harmful and shorten the service life.
When calibration is useless: 3 cases
Before you spend time on the procedure, check if your case makes it to this list:
- Physical wear of the battery. If the smartphone holds a charge of less than 4-5 hours in moderate use, and in Settings → Battery → Battery capacity shows less than 70% of the original battery state, calibration will not help. We need a replacement.
- Software bugs MIUI. After major updates (e.g., with the MIUI 13 on MIUI 14) the system may not display charge correctly. Try resetting the battery settings first.
| Symptoms. | Possible cause | Do you need calibration? |
|---|---|---|
| The phone is turned off at 15-30% | Controller's out-of-synchronization | ✅ Yes. |
| Battery discharged in 2-3 hours | Battery wear or background processes | ❌ No (check the capacity) |
| Charge 'stuck' by 80% | BMS Failure or Slow Charging Mode Enabled | ✅ Yes (if the mode is off) |
| Interests will jump after rebooting | Battery cache error | ✅ Yes. |
Method 1: Resetting battery data via MIUI (the safest)
This method works on all Xiaomi, Redmi and POCO smartphones with MIUI 12 and later. It resets the charge controller cache without affecting user data.
Charge your phone to 100% | Turn off battery optimization for system applications | Connect to the network (during the procedure) | Don't interrupt the process
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Instructions:
- Open Settings → Battery and Performance → Battery status.
- Slip on the three points in the upper right corner and select Battery Data Reset (some models call it Calibration).
- Confirm the action and wait for the reboot (it will take 1-2 minutes).
- After turning on, discharge the phone until it turns off automatically (not to 0% on the screen!).
- Charge up to 100% without interruptions (use the original adapter).
💡
If there is no Battery Data Reset, try the alternative path: Settings → About Phone → MIUI version (tap 7 times to turn on Developer Mode), then go back to Settings → Additional → For Developers → Battery Data Reset.
⚠️ Warning: Do not use this method more than 1 time in 3 months! frequent discharges can lead to accelerated degradation of lithium polymer batteries.
Method 2: Manual calibration via ADB (for advanced)
If standard reset didn’t work, try forced calibration via Android Debug Bridge, which requires ADB and a little bit of technical skill, but gives a more accurate result.
What you need:
- 🖥️ Computer with Windows/macOS/Linux.
- 🔌 Cable USB Type-C (preferably original).
- 📥 Utility. ADB Tools (download Platform Tools from Google).
- 🔧 Initiated Debugging Mode USB smartphone.
Step-by-step:
- Turn on USB Debugging: Settings → About Phone → MIUI Version (Tap 7 times) Settings → Additional → For Developers → Debugging on USB
- Connect your phone to your PC and confirm your trust in your computer.
- Open the command prompt (cmd) in the folder with ADB and type: adb shell su dumpsys battery set ac 1 dumpsys battery reset (If it requests root access, but it does not, skip the su command).
- Turn off the cable and discharge the phone before it turns off.
- Charge to 100% without interruption.
What are ADB teams doing?
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The ADB method is more effective than standard reset because it works directly with Android system files, but if used incorrectly, it can cause charge sensors to malfunction.
Method 3: Complete discharge/charging cycle (Li-Po batteries only)
This is a method that is often recommended on the Internet, but it's dangerous for modern batteries if you do it wrong, and we'll describe a safe option that doesn't damage the battery.
What needs to be done:
- Charge your phone to 100% original adapter.
- Disable all battery optimizations: Settings → Battery → Battery Optimization → Select “All apps” → Turn off optimization for system processes
- Discharge your phone before automatically turning it off (don’t turn it on until you plug in the charger!).
- Charge to 100% without interruptions (at least 2-3 hours after reaching 100%).
- Repeat the cycle 1 more time (total 2 full cycles).
⚠️ Warning: Never discharge your phone to 0% intentionally! Xiaomi's lithium polymer batteries are designed to operate in the range of 20-80%. Deep discharges reduce lifespan by 10-15% per cycle.
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To speed up the discharge, turn on Airplane Mode, maximum screen brightness, and run a performance test (e.g., 3DMark or Geekbench).
Top.-5 Calibration errors (and how to avoid them)
Many users are making battery problems worse, and they're following the "advice" from the old forums.
- 🚫 Using the Play Market’s “quick calibration” apps, apps like Battery Calibration or AccuBattery can’t physically change data. BMS — They just reset the Android cache, like the standard method, and some of them contain malicious code.
How to check if calibration has helped
After the procedure, you need to evaluate the result. Here are 3 ways to test:
- Run a video on YouTube at 1080p at 50% brightness and Wi-Fi. If the phone ran out in 4 hours before calibration and then 5-6 hours after, the procedure worked.
- Check in AccuBattery. Install the AccuBattery app and see the discharge schedule. Once it's successfully calibrated, it should be smooth, without any sudden jumps.
- Diagnostics in ##4636##. Type this code in the dialer, go to Battery Information and check the charge level setting. It should match the percentages in the notification panel.
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If the problem persists after calibration, check the battery status in Settings → Battery → Battery status. If the capacity is below 80%, you need a replacement.