The Xiaomi Redmi Note 8, released in 2019, is still a popular device due to its excellent price-performance ratio, but over time, users begin to notice strange battery behavior: the screen can show 20% charge, after which the phone suddenly turns off, or the charging process “stuck” by 99% and does not go to 100% even after a few hours of connection to the network.
The process of restoring the correct display of energy levels is called calibration, and for the Redmi Note 8 model it is especially relevant because of the peculiarities of the MIUI shell. The Android operating system does not always read data from the power controller correctly, which leads to incorrect planning of energy consumption by background processes. Calibration does not restore the physical capacity of the worn battery, but causes the system to re-rewrite the tables of compliance with voltage and percentages.
In this article, we will go into detail about all the available ways to fix this problem, from simple methods without root rights to advanced manipulation through the engineering menu and the computer. You do not need to be an expert in programming to perform these actions, but it requires attentiveness and accurate follow-up of instructions. Ignoring the problem can lead to you being left without communication at the most inopportune moment when the indicator was still showing full charge.
Diagnostics of the battery before the start of work
Before you start software manipulation, you need to make sure that the problem is software failure, not physical wear or damage to hardware components. Physical wear and tear of Li-Ion cells is inevitable: after 500 charge-discharge cycles, the capacity drops to about 80% of the original. If your Redmi Note 8 is several years old, the decline in autonomy is a natural process of aging battery chemistry.
Check the current status through a hidden engineering menu that is built into the MIUI firmware. To do this, open the Phone app and dial the combination ##6485##. In the list of parameters that opens, you should be interested in several key indicators that will tell you more about the health of the power system than the standard indicator in the corner of the screen.
Pay special attention to the parameters MB_06 (battery status; and MF_02 (charger cycle counter if in the field MB_06 It says "Good," and it's physically good, but if you see a bad value or more cycles, it's good. 600-700, No software calibration will return the previous autonomy – you will need to replace the element.
- 🔋 MB_06 — Shows the overall health of the battery (Good/Bad).
- 🔢 MF_02 — Number of complete recharge cycles traveled by the device.
- ⚡ MB_00 — The current percentage of charge the system sees.
- 🌡️ MF_05 — Current battery temperature (critical for safety).
⚠️ Note: If the battery temperature is (MF_05) higher 45 Celsius at rest, immediately stop using the device. Exploitation of the overheated Redmi Note 8 It can cause battery swelling or fire.
It’s also worth checking if a particular application is causing the quick discharge. Go to Settings → Battery and Performance → Energy Consumption. If you see an application that consumes a disproportionate amount of resources (e.g., 30-40% per hour of downtime), the problem may be a software bug or virus, not a calibration need.
Classic Calibration Method Without Root Rights
The safest and most recommended way for the manufacturer to reset the meter does not require third-party software or superuser rights, but relies on the device's natural discharge and full charging, allowing the power controller to redefinition the limits of capacity. The algorithm is simple, but it takes time and patience, because the process cannot be interrupted.
To start, fully discharge your Xiaomi Redmi Note 8 to the point where it will turn off on its own. If the phone shows, for example, 15% and goes out, try turning it back on and discharge further until the screen stops responding to the power button.
Leave the phone to charge until the indicator shows 100%. Once this value is reached, do not turn off the cable immediately - leave the device on charge for another 1-2 hours. This is necessary to ensure that the saturation currents ("drip charging") equalize the voltage in all cells of the battery, which is especially important for older batteries.
☑️ Checklist of classical calibration
After you've been charging your phone for a while, force the reboot by holding the Volume Up + Power button combination. When the system boots up, check the charge level again. If it drops below 100%, repeat the charging cycle. This method allows you to rewrite the values in the batterystats.bin file, which stores battery usage statistics.
Using applications to calibrate the battery
For users who want to automate the process or get more detailed statistics, there are specialized applications from the Google Play Store. One of the most popular and proven tools is Battery Calibration or analogues like AccuBattery. These programs help to more accurately determine the real capacity and reset the meter errors.
The way these applications work is to monitor the charging process and send a command to reset the stats when the battery reaches 100%. Some require root rights for deep calibration, but the basic features are available on standard firmware. Installing third-party software always carries risks, so download the applications only from official sources.
Once you install the app, run the full discharge and charge cycle under its control, and the program will tell you when to turn off the charger, and it is important to understand that these utilities do not magically treat the battery, but only correct the displayed data in the MIUI interface.
Do I need root rights for applications?
⚠️ Warning: Avoid apps with names like Ultra Fast Charger or Battery Saver Pro that promise to increase capacity by 50.
Deep Calibration with Recovery Mode and ADB
For advanced users who aren’t afraid to work with the command line, there is a more effective method of resetting battery statistics through debugging. USB (ADB). This way you can interact directly with Android system files without the limitations of the user interface, USB-cable and installed drivers ADB.
First, activate the developer mode on Redmi Note 8. Go to Settings → About Phone and press 7 times on MIUI Version. Then, in the “Additional” menu, turn on “Debugging on USB.” Connect the phone to your PC and allow debugging on your smartphone screen.
Open the command line on your computer in the ADB folder and enter the command to log in to the shell: adb shell. Next, find and delete (or rename) the battery statistics file. Depending on the version of Android and MIUI, the path may differ, but most often it is /data/system/batterystats.bin.
adb shell
rm /data/system/batterystats.bin
rebootOnce you reboot, the phone will restart and the statistics will be cleaned, and the system will start collecting energy consumption data from scratch, which is especially useful if the standard calibration has failed and you are sure that the problem is software.
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Use only original or certified USB cable. Cheap cables can have high resistance, resulting in a voltage drop and incorrect operation of the charge controller during calibration.
Analysis of the impact of MIUI updates on autonomy
Often, battery problems on the Redmi Note 8 occur after an operating system update. Newer versions of MIUI may contain optimizations that do not work properly with older firmware versions or specific battery revisions. After a major upgrade, the system takes time (usually 3-5 days) to re-index files and adapt energy saving algorithms.
During this period, the phone can heat up and discharge quickly. If the problem persists for longer than a week, consider rolling back on the previous version of the firmware or, conversely, installing a more recent build where the bug could be fixed. You can check the relevance of the software in the Settings menu → About the phone → MIUI version.
There is a compatibility table and known autonomy issues for different MIUI versions on the Redmi Note 8:
| MIUI version | Android version | Battery stability | Known problems |
|---|---|---|---|
| MIUI 11 | Android 9 | Tall. | Rare interface freezes |
| MIUI 12 | Android 10 | Medium | High cost standby |
| MIUI 12.5 | Android 11 | Low. | Overheating during charging |
| MIUI 13/14 | Android 12/13 | Medium | Incompatibility of old applications |
If you think the problem started right after the update, you should do a full Wipe Data reset with a pre-backup, which will remove the conflicting settings left over from the old version of the system, and remember that this step will delete all your photos, contacts, and apps.
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After the system update, be sure to give the phone 2-3 days to adapt. Aggressive calibration in the first hours after the update can disrupt the learning process of energy saving algorithms.