Xiaomi’s smartphones, including Redmi and POCO, are known for their energy efficiency, but over time, any lithium-ion battery loses its original performance. Users often face a situation where the device discharges faster than the manufacturer’s stated time or shows an incorrect percentage of charge. In such cases, there is an urgent need to check the real capacity of the battery to see if a replacement battery or software calibration is required.
There are several ways to access battery technical information, from built-in engineering menus to using specialized software on a computer. The nominal capacity specified in the specifications often differs from the actual capacity available after thousands of recharge cycles. Understanding the current state of the chemical current source allows for timely maintenance.
In this guide, we will discuss in detail all available diagnostic methods, starting from simple ones. USSD-and ending with professional analysis through ADB. You will learn to distinguish software failures from physical wear and tear and learn how to extend the life of your device.
Use of the engineering menu and USSD-code
The fastest way to access hidden diagnostic information is through the use of special engineering code, which requires no third-party application installation and works on most devices with a MIUI or HyperOS shell. To activate, you need to open the standard Phone application and type the combination ##6485##.
Once you enter the last star, the Battery Info menu will automatically open. There are a lot of options here, but for the average user, only a few key metrics are important. The interface may vary depending on the firmware version, but the basic notations remain unchanged across different models.
- 📱 MB_06 — displays the state of the battery (good means normal state).
- 🔋 MB_00 — current charge level as a percentage.
- ⚡ MB_01 — current battery voltage in millivolts.
- 📉 MB_02 — Current current strength (positive when charging, negative when discharged).
It is important to understand that not all codes work the same on all devices. On some newer models with a secure shell, access to the full list of parameters may be limited by the manufacturer for security reasons. If the code does not work, try entering it in dial mode, rather than in contact search.
⚠️ Attention: In the engineering menu are not only information fields, but also test functions. It is strongly recommended not to change the values in the fields, the purpose of which you do not know, as this can lead to incorrect operation of the power management system.
Special attention should be paid to parameters that show the calculated capacity. In some versions of the menu, you can find rows. MF_02 (the design capacity at full charge) and MF_05 (Comparing these values to factory data gives a primary view of battery health.
Analysis through the “About Phone” menu and statistics
A more accessible, but less informative way is the standard settings menu. The MIUI shell provides basic statistics that help you estimate the energy consumption rate of specific applications. Go to Settings → Battery to see the consumption schedule.
You won't find exact capacitance figures in mAh here, but you can analyze consumption patterns. If the graph shows a sharp jump or unreasonably high consumption in standby mode, this may indicate a software conflict or battery degradation that does not have time to give current evenly.
The Consumption section displays a list of applications sorted by energy used, which reveals “gluttonous” programs that can disguise themselves as background processes and drain battery life, often after deleting such applications, the device’s autonomy increases significantly without replacement.
- 📊 Click on the chart to see the hourly breakdown of the expenditure.
- 🔍 Use the search in the settings for “Battery” for quick access.
- 🛡️ Check the "Security" section» → «Optimization for Automatic Closing of Background Processes.
It is worth noting that the built-in statistics can sometimes be inaccurate due to the nature of the Android system, which aggregates data with a delay.
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Turn on Power Saving Mode at night if you don't wait for important calls, which will limit background synchronization and keep you charged until morning.
Software Methods: AccuBattery and AIDA64 Utilities
To get the most accurate data on the actual capacity without a computer connection, it is recommended to use specialized applications from the Google Play Store. The leader in this field is AccuBattery, which uses algorithms to calculate the real capacity based on charging cycles.
The way these applications work is by monitoring the current flowing into the battery while charging, and because the smartphone's power controller knows exactly how much power has been taken in, the app summarizes these values, but it takes time to get reliable data, usually several full-discharge and charge cycles.
Another popular utility is AIDA64. It provides a snapshot of the device's technical specifications, including current capacity, voltage, temperature and battery chemistry. Unlike AccuBattery, AIDA64 shows current parameters read directly from the controller.
The path to information in AIDA64:
Display → Battery → Health
(Represents state: Good/Overheat/Dead)
Current Capacity (Current Capacity)
Voltage (Voltage)Using third-party software has its advantages: user-friendly interface, history of changes and clear graphics, but it is worth remembering that such applications consume the resources of the device themselves, working in the background and collecting data.
☑️ Checking the battery health through software
Diagnostics through computer and ADB
For advanced users who want to get the most complete data without installing unnecessary apps on a smartphone, the ideal solution is to use USB debugging and ADB (Android Debug Bridge) tools, which requires a PC and installed drivers.
The first step is to activate the developer mode. To do this, go to Settings → About Phone and quickly click on the build number (MIUI Version) seven times. After that, the "For Developers" option will appear in the "Additional" menu, where you need to turn on "Debugging by USB".
Once you connect your smartphone to your computer, open the command line or terminal in the ADB folder and type in a command to get a battery dump, and this command will output a list of all the parameters that the power controller communicates to the operating system.
adb shell dumpsys batteryIn the output, you are interested in the lines level, scale, voltage, and temperature. Although this command does not always show the exact capacity in mAh directly, it allows you to see the raw data that the system uses to plot.
A deeper analysis is possible by reading system files if the device has root rights. /sys/class/power_supply/battery/capacity or similar paths depending on the manufacturer of the power controller.
⚠️ Attention: When working with ADB Be careful with commands that change battery settings (e.g. forced charging level settings) this can knock the controller calibration and the phone will show an incorrect percentage.
Data interpretation: norm and wear
With the numbers, many users are puzzled: Is this normal? For lithium-ion batteries, the standard is losing about 20% of capacity after 500 full charge cycles. If your phone lasts more than two years, reducing capacity by 15-25% is a natural physical process.
Critical is when the residual capacity drops below 70-80% of the factory, in which case the smartphone can suddenly turn off at 15-20% of the charge, as the voltage under load drops below the shutdown threshold, and reboots when the camera starts or heavy games are possible.
| Parameter | Normal value. | Sign of wear and tear. | Critical condition |
|---|---|---|---|
| Residual receptacle | 90-100% | 75-85% | Less than 70% |
| Tension (calm) | 3.7. to 4.2 B | 3.6. to 3.7 B | Below 3.5 B |
| Temperature (load) | 35 - 45 °C | 45 - 50 °C | Above 55°C |
| Charging cycles | 0 - 300 | 300 - 600 | More than 800. |
It's important to take temperature into account. High temperature is the main enemy of Li-Ion chemistry. If you notice that the phone warms a lot even on simple tasks, it can accelerate battery degradation regardless of the number of cycles.
What is the memory effect?
Calibration and extension of service life
If the diagnostics show that the physical capacity of the battery is normal, but the phone is behaving strangely (switches off by 30%, charges for a long time at the end), the calibration of the controller may have gone wrong, in which case the full calibration helps.
The calibration process is simple: discharge the device until it is completely turned off, then charge it when it is turned off to 100%. Then turn on the phone without removing it from the charger, and make sure that the indicator shows 100%, a procedure that helps the system to re-determine the voltage boundaries.
To extend battery life in the future, follow a few simple rules: Avoid deep discharge to zero and don't keep your phone constantly charging at 100%. The optimal range for storage and daily use is between 20% and 80% charge.
- 🌡️ Avoid overheating: Do not play heavy games while charging.
- 🔌 Use original or certified cables and power supplies.
- 📱 Disable unused functions (GPS, Bluetooth, NFC) load-reducing.
Compliance with these recommendations will significantly increase the interval between battery replacements. Remember that the battery is an expendable material, and replacing it after 2-3 years of active use is normal maintenance practice.
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Regular capacity checks allow you to plan your battery replacement in advance and avoid sudden shutdowns at an important time.