Xiaomi Redmi Note 8 Pro came to market with an impressive 4500 mAh battery, which for many users was a decisive factor in the purchase. However, over time, even the most reliable lithium polymer battery loses its original capacity, and the device begins to run out faster. Many owners wonder how to accurately know the current state of the power system without opening the case of the gadget.
Android and MIUI do not have a single “Show battery health” button as implemented in iOS. However, there are several proven methods to access technical information about the energy storage device. We will look at both standard diagnostic tools and more advanced ways for power users.
Understanding the actual state of your battery is critical to planning replacement or optimizing system settings. Chemical degradation is a natural process, but knowing the exact numbers will help avoid sudden shutdowns when the battery is low. In this article, we will take a look at every method available.
Staff diagnostic tools in MIUI
The first place a Redmi Note 8 Pro user should look is the built-in Security app. Xiaomi has integrated a basic analysis tool that allows you to assess the overall condition of the device, including power parameters. To start the diagnosis, you need to open the application and select the "Verification" or "Diagnostics".
The system will scan all the nodes, including the battery, quickly, but it's only normal or bad, without giving you accurate milliamp-hour numbers, a surface check that's good for quick detection of critical faults, but not for accurate measurements.
More detailed, though still approximate, data can be found in the Battery menu in the main settings, displaying screen time and consumption statistics, but not physical capacity.
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If the built-in diagnostic shows a battery error, try calibrating first: discharge the phone to 0%, then charge to 100% when off.
Use of the engineering menu and USSD-code
One of the fastest ways to access hidden information is to enter special codes in the Phone app. Xiaomi devices run universal code ##6485##. Once it is entered on the screen, the Battery Info window will automatically open, containing many technical parameters.
In the list you need to pay attention to the following lines:
- 🔋 MB_06 — The state of the battery (Good, Bad, Unknown).
- 🔋 MB_00 — current charge level as a percentage.
- 🔋 MF_02 — Number of full recharge cycles (Cycle Count).
- 🔋 MF_05 — actual current battery capacity in mAh (not available on all firmware versions).
- 🔋 MF_06 — factory (nominal) battery capacity.
It is important to note that on new versions of the shell MIUI Some fields, especially those concerning the exact capacity (MF_05), It can be hidden by developers or display zero values, in which case the code will only show the number of cycles and the overall status, which is still valuable information for assessing wear and tear.
What if the code doesn't work?
Checking through ADB and computer
For users who need the most accurate data, the ideal solution is to use the Android Debug Bridge debugging bridge (ADB). This method requires connecting the smartphone to the computer through USB-It's a cable, and it has a minimum set of drivers, and it allows you to read data directly from the system files in the battery.
First, activate the developer mode. Go to Settings → About Phone and quickly click on the MIUI Version seven times. After you have become a developer, go to the advanced settings and turn on the USB Debugging option.
☑️ Preparation for work with ADB
After connecting and configuring the environment, you must enter a command to read the battery properties file in the computer command line (terminal).
adb shell dumpsys batteryIn the output of the command you will find the lines scale (maximum charge, usually). 100), The charge counter is the current charge in mAh. To know the full capacity, the phone must be charged at a charge counter. 100%. If the charge is not full, then mathematically recalculate the value. /sys/class/power_supply/battery/capacity interest.
⚠️ Attention: Use ADB Enter the commands exactly as the instructions say. Do not try to change the values in the system files without deep knowledge, as this can lead to incorrect operation of the power controller.
Third-party monitoring applications
If you don't want to mess with code and computer, specialized applications from the Google Play Market come to the rescue, and they use the standard APIs of the system to collect statistics and present them in a convenient way, and AccuBattery is considered one of the most popular and reliable solutions.
The way it works is by analyzing the charging process, and it doesn't know the capacity of your battery from the factory, it calculates it by measuring how many milliamp hours it entered from the moment it started charging to 100%, so you need to run multiple charging and discharging cycles with the application running to get an accurate result.
Other useful applications include Battery Charge Limit (for advanced users who want to limit charge) and 3C Battery Manager.
- ⚡ Heating temperature of elements in real time.
- ⚡ Discharge rate in mA/h under different use scenarios.
- ⚡ History of charge cycles and calculated wear in percentage.
It is worth considering that third-party programs can consume additional charge on their own, since they require constant access to sensors, and it is recommended not to keep such applications in an active background constantly, but to run them periodically for diagnosis.
Analysis of logs and system files
For the most meticulous users who own Root (full system access), all configuration files are open. 8 Pro with unlocked bootloader can access files stored along the way /sys/class/power_supply/battery/. Here are files read by the system to display status.
Interest is the files charge_full (current full capacity) and charge_full_design (By comparing these two values, you can get a mathematically accurate percentage of wear and tear. Files are text format and can be read by any file manager with superuser rights, such as Root Explorer or Root Explorer. MT Manager.
| Parameter | File in the system | Description of meaning | |||
|---|---|---|---|---|---|
| Current capacity | charge_full | Real capacity at the moment (decreasing over time) | |||
| Factory capacity | charge_full_design | New battery capacity (4.5 million mAh for Note 8 Pro) | Wearing | Calculated. | Difference Between Design and Full |
| Temperature. | temp | Temperature in tenths of a degree (e.g. 300 = 30.0°C) |
Root rights automatically disqualify warranties and carry security risks. If you're not sure what you're doing, you'd better limit yourself to methods without getting super-user rights. However, for accurate diagnosis before replacing a battery, this method is the gold standard.
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Files in the directory /sys/class/power_supply/ contain the most accurate data available on the system, but require Root permissions to access.
Interpretation of results and norms of wear
Once you get the capacity figure, it's important to interpret it correctly. Lithium polymer batteries installed in the Redmi Note 8 Pro are considered serviceable if their residual capacity is more than 80% of the factory capacity. For a 4500 mAh battery, a critical threshold is around 3600 mAh.
If you wear more than 20-25%, you will notice a significant reduction in battery life, and signs of degradation include:
- 📉 Sharp jumps in percentage charge (for example, from 30% immediately to 10%).
- 📉 Turning off the phone when charging 15-20%.
- 📉 Battery bloating (requires immediate replacement!).
The battery life averages 2-3 years of active use (about 500-800 full cycles), after which the chemical composition of the electrolyte degrades, and it is impossible to restore the capacity by software methods ("calibration") - physical replacement of the element is required.
⚠️ Warning: If you find that the back cover of the smartphone has started to move away or the body has deformed, immediately stop using the device.The billowing battery is fire-prone and can damage the display or motherboard.