Xiaomi, Redmi and Poco are known for their high energy efficiency and fast charging, but any lithium-ion power source degrades over time. Users often notice that the device begins to discharge faster, unexpectedly turn off in the cold or stay at 1-2% of charge for a long time. These are the first signals that battery capacity has decreased and the resource is coming to an end.
Unlike the iPhone, where battery health is available in a few clicks, the MIUI or HyperOS shell often hides that information from the eyes of the average user. Engineers suggest that the average owner does not need to know the exact numbers of voltages or recharge cycles. However, for those who want to objectively assess the wear of their gadget before buying a used model or plan to replace, there are proven diagnostic methods.
In this article, we will discuss all available methods: from simple codes in the engineering menu to deep analysis through the use of the software. ADB-You'll learn to distinguish between software calibration failure and actual physical wear and tear of a chemical element, and understanding the current state of the power grid will help you extend the life of the device or make an informed decision about its maintenance.
Use of the engineering menu and USSD-code
The fastest way to access hidden diagnostics is to use special codes. Xiaomi smartphones have built-in engineering menus that allow you to current parameters of the iron. To enter it, you need to open a standard call and dial the combination ##6485#. Once you enter the last character, the menu should open automatically, without the need to press the call button.
In the list of parameters you are interested in a line with the designation MB_06. This is the parameter that shows the current state of the battery in text, like, "Good." If you see a Bad or Replace status, it's a direct signal of critical wear or malfunction of the power controller. MB_00, which shows the current percentage of charge, and MF_02 — number of full recharge cycles.
Note that newer versions of HyperOS firmware or some regional builds may have limited or modified access to this menu. If the code doesn't work, try the alternative ##4636## that leads to the testing menu, and select Battery information where you can see the basic voltage and temperature data.
⚠️ Warning: Be careful about the engineering menu. Changing parameters you're not sure about (especially those related to calibration or resetting statistics) can cause the charging system to malfunction!
For users who want more detailed statistics, there is another code, ##4626##. It opens the testing menu, where you can run an automatic test in the Battery Test section, the system will evaluate the battery's ability to hold the load and give a preliminary verdict. This is a great way to quickly check the phone before buying from hand.
Analysis through the Security Application
The standard Security app, which is pre-installed on all Xiaomi devices, has a built-in but not always noticeable diagnostic tool. Unlike third-party utilities, it has deep access to system logs and can more accurately estimate temperature and energy consumption in real time. To begin analysis, open the application and go to the Battery section.
Here you'll see a graph of consumption and a list of the most energy-intensive applications. However, the hidden diagnostic function is often activated only after a specific use case or is available in an extended menu. Click on the three dots in the upper right corner and select "Statistics" or "Diagnostics." The system will run a quick scan and may issue a warning if it detects an abnormal discharge or overheating.
It's important to understand that the full-time analyzer is focused on finding "gluttonous" applications, not measuring physical capacity. If the system says "everything is fine," it doesn't guarantee that the physical capacity of the battery has not dropped to 70% of its nominal value. Software optimization can hide real problems by redistributing resources.
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If the Security app shows abnormally high consumption by the Android system or the MIUI process, try resetting the network settings or clearing the system cache.
For a deeper analysis, the Safety app can use the Optimization feature, which will close the background processes and restart services, which sometimes helps recalibrate the display of the percentage of charge, this is especially true if the charge indicator “downloads” or the phone turns off at 15-20%.
Checking through ADB and computer diagnostics
The most accurate and professional method available to advanced users is using USB debugging and the ADB command line, which allows you to pull raw data directly from the kernel system files without the interface constraints. First, you need to turn on the developer mode: seven times click on the build number in the About Phone section.
Once you have enabled the developer mode, activate the USB Debugging option. Connect your smartphone to your computer with a cable. The PC must have Xiaomi drivers and the ADB platform installed. Open the command line and enter a command to check battery status:
adb shell dumpsys batteryThis command will give you a huge list of parameters. You're interested in the lines level (current charge), scale (maximum scale, usually 100), status (charge status) and health (state). Health = 2 means "Good" and health = 1 - "Unknown".
adb shell cat /sys/class/power_supply/battery/capacityHowever, to find out the real residual capacity (Design Capacity vs Current Capacity), it is often necessary to access root rights or use specialized scripts that parse files from the folder. /sys/class/power_supply/. No root rights. ADB The data will show mainly programmatic values, but the health status is a reliable indicator of a controller malfunction.
What to do if your computer can’t see your phone?
Third-party monitoring applications
If you don't want to mess with code and command line, you'll find specialized applications from the Google Play Store that have been led by AccuBattery for years, and it's different from system utilities, because it doesn't know the exact capacity of your battery in the first place, but it calculates it in the process.
Once installed, AccuBattery starts tracking each charge cycle, and it compares the amount of energy that has "entered" into the battery (read from the charging controller) with the change in percentages. After 3-5 charging cycles, the program gives a fairly accurate estimate of the actual capacity in mAh, which allows you to see how much percent of the factory capacity has lost your device.
Other useful utilities include Battery Health and Cpu-Z. In Cpu-Z, you need to go to the Battery tab, where the battery type is indicated in the Technology field and the state of the battery is indicated in the Health field, but the data here are often duplicated system data and may be less accurate than AccuBattery's calculated data.
- 📱 AccuBattery: The best choice for estimating real wear in percentage, requires multiple charging cycles for calibration.
- 🔋 Cpu-Z: Useful for viewing technical voltage, temperature and current status without unnecessary graphics.
- ⚡ 3C Battery Manager: A powerful tool for advanced users, able to build complex discharge graphs and wake up the device on schedule.
⚠️ Warning: Third-party applications require constant access to the system and can consume battery power themselves.If your goal is to maximize your running time, use them only temporarily for diagnostics, and then delete them.
Visual Diagnosis and Physical Signs
Software methods are good, but the physical condition of the battery often says more than the numbers. Lithium polymer batteries used in Xiaomi are sensitive to overheating and mechanical stress. The first sign of degradation can be bloating. If the back of the smartphone begins to move away from the case or the screen slightly raised, this is a critical situation.
A billowing battery is strictly forbidden to charge or pierce, as this can lead to fire, and you can visually see this by putting the phone on a flat surface and trying to spin it: if it rotates like a yule, then the battery is inflated and rests on the table only one corner.
Other physical signs include:
- 🌡️ Excessive heating: If the phone warms up in the area of the camera or center of the case even on light tasks (browser, messengers), this is a sign of high internal battery resistance.
- 📉 Nonlinear discharge: A sharp percentage jump (e.g., from 40% to 15% or 25% off) indicates a “memory effect” or damage to one of the cells.
- 🔌 Charging problems: If the phone is long dialing the last 10-15% or quickly resets them at the start of use, the controller cannot balance the cells properly.
☑️ Checklist of visual inspection
Table of normal and critical indicators
So to make it easier for you to navigate the data, we've created a table that can help you interpret the values that you get from an engineering menu or an application.
| Parameter | Normal value. | Critical significance | Recommendation |
|---|---|---|---|
| Health (status) | Good (2) | Bad / Overheat / Dead | Replacement with any value other than Good |
| Temperature. | 25°C - 35°C | Above 45°C at rest | Stop using, check background processes |
| Charge cycles | 0 - 300 | More than 500-600. | Capacity dropped to ~80%, it's time to think about replacing |
| Tension. | 3.7B - 4.4B | Below 3.4V or higher than 4.5V | The risk of deep discharge or overcharging |
Note that the 4.4V to 4.5V voltage is typical of the fully charged state of modern fast batteries, but if it is held constantly, it is a controller malfunction. The normal operating range in active use is 3.6V to 4.2V.
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Regular battery checks prevent sudden shutdowns and potential damage to the body from a swollen battery.
Tips for extending battery life
After diagnosis, it is important to know how to save the remaining resource. Xiaomi batteries are sensitive to extreme states of charge. Try not to keep the phone constantly on charge after reaching 100% and do not discharge it to zero. The optimal range for long-term storage of chemical activity is from 20% to 80%.
Use original or certified cables and power supplies. Cheap counterparts from the market often do not have proper protection against voltage surges, which kills the power controller inside the smartphone. Also avoid using the phone during intensive charging, especially in heavy games, as the combined heat from the processor and battery destroys the electrolyte.
If you don't plan to use your phone for a long time, leave the charge at 50-60% and turn off the device. Storing a fully discharged or fully charged phone off leads to irreversible chemical reactions and loss of capacity.