How to check the battery of the Xiaomi phone: expert guide

Declining autonomy is one of the most common problems faced by Xiaomi and Redmi smartphone owners after a year of active use. Users often notice that the device discharges faster, warms up while charging or suddenly turns off at 15-20% charge. Diagnosing the battery is the first and most important step before deciding whether to buy a new energy storage device or the entire device.

Unlike many other manufacturers, the Chinese company provides users with advanced tools for self-analyzing the health of the power system. You do not need to immediately carry the gadget to the service center, since the built-in mechanisms allow you to get accurate data on charging cycles and current capacity. In this article, we will analyze all the available methods, from simple engineering codes to deep analysis of system logs.

It is worth noting that the lithium polymer cells used in modern Mi and Poco have a limited lifespan. Proper and timely battery testing helps to extend the life of the device and avoid unpleasant surprises in the form of a sudden shutdown. Let's look at the basic methods of assessing the state of the unit.

Use of secret codes and engineering menus

The fastest way to access hidden diagnostic features is to use special diagnostics. USSD-In the firmware. MIUI And HyperOS has a special code reserved that opens the hardware testing menu. To run, you need to open the Phone app and type the combination ##6485##. Once you enter the last star, the menu should open automatically, you don't need to go anywhere.

In the window that opens, you'll see a lot of parameters, but we're only interested in a particular block of information. Don't try to change the values in other sections if you're not sure about your actions, because this can lead to malfunctioning of the system. MB_06, displaying battery status.

⚠️ Note: If the menu does not open after entering the code, it is possible that your version of the shell does not support this command or it is blocked by the carrier.

If the code didn't work the first time, check whether Do Not Disturb or lock input is enabled, and some global firmware versions may have limited access to the engineering menu, and in such cases, you should pay attention to standard system tools or logs.

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If the ##6485### code doesn’t work, try entering it in the Testing app (CIT), which is often pre-installed on Xiaomi devices in the Tools folder.

Decoding of key parameters MB_06 and MB_00

Once you've successfully logged into the diagnostic menu, you'll see a list of technical data, most of which are service data and don't carry a payload for the average user. MB_06 and MB_00.

Parameter MB_06 It shows the current state of the battery in text format. Ideally, it should say "Good." If you see "Bad" or "Replace," it's a signal of critical wear or malfunction of the controller. MB_00 displays the current percentage of charge, which may differ from what the widget on the desktop shows, which sometimes helps reveal the calibration of the indicator.

You should pay special attention to the parameters associated with temperature. MB_08 (current) significantly exceeds MB_09 (maximum recorded) at rest, this may indicate problems with the charge controller or background processes overheating the device. 25 before 35 degrees Celsius at moderate load.

If you just plugged in a charger, give the system 1-2 minutes to stabilize the readings before taking the measurements, which will allow you to get more objective data about the state of the system.

Analysis of the state through the settings of the MIUI system

Xiaomi is gradually adopting friendlier interfaces to monitor energy, hiding complex codes from the eyes of the average user. New versions of the HyperOS shell and the latest MIUI have a built-in verification feature that is available through the standard settings menu, which is the most secure method that does not require commands.

To access this information, go to Settings, then select About Phone, and you will find a line called "Battery" or "Battery Status" (location may vary depending on the OS version), clicking on it, the system will make a rapid diagnosis and give a verdict: "Normal", "Good" or "maintenance required".

This is a good way to do this, but it's less informative than an engineering menu, it won't tell you the exact number of cycles or the actual capacity in milliamp hours, but it's enough to quickly check the battery's health, and if the system says it's in good condition and the phone shuts down 20 percent, the problem might be a software calibration failure.

Also in the Battery section, you can find a power graph in the settings. Sharp jumps in the graph, not associated with active screen or application use, can indicate chemical degradation of cells when the voltage drops nonlinearly, an important sign that the Li-Pol element is approaching the end of its life.

Software diagnostics with ADB and logs

For advanced users who want to get the most accurate data that is not available in a conventional interface, there is a method of analyzing system logs through USB debugging. This method requires connecting a smartphone to a computer and the presence of an ADB utility (Android Debug Bridge), which allows you to “pull” hidden information directly from the kernel of the system.

First, you need to activate the developer mode. To do this, quickly click on the build number seven times in the About Phone section. Then, in the Developer menu that appears, turn on Debugging by USB». After connecting to the PC, execute a command to read the file battery_log or viewing status through shell.

adb shell dumpsys battery

This command will provide a detailed report on the current status. Pay attention to the lines level, scale and status. A deeper analysis is possible through reading the log files, where the history of charging cycles is stored. However, this method requires caution: misinterpreting the data can confuse the user.

⚠️ Attention: Use of teams ADB Do not attempt to execute commands to write or modify system files unless you are an expert, as this may result in loss of warranty or "bricking" of the device.

The advantage of this method is that it works even on devices that have locked the engineering menu, and you get raw data directly from the power controller, which is especially useful when you buy a used phone, where the seller could programmatically reset the cycle counter in the engineering menu, but not in the system logs.

Third-party applications for accurate capacity measurement

If the built-in tools don't seem informative enough, Google Play's specialized applications come to the rescue, and AccuBattery is the leader in this field, and it doesn't just read data, it analyzes the charging and discharging process in real time, calculating the real capacity based on consumed mAh (consumed milliamps).

These applications are based on coulonometry, which tracks how much energy has been poured into the battery from the moment the charging screen is turned on to 100%, and compares this to a change in percentage of charge. To get accurate data, you need to use the application for several days, performing full cycles of discharge and charge.

Other popular applications, such as Ampere or Battery Health, can also be useful. They show the current of charge in real time, which helps to identify problems with the cable or power supply. If the charge current is significantly lower than stated (for example, 0.5 A instead of 2 A for fast charging), this can indicate the degradation of the battery or controller.

Critical: No application can show 100% accurate capacity without a hardware calibrator, but AccuBattery gives a margin of error of only 3-5%, which is a great indicator for software evaluation.

Using third-party software, you can visualize data in the form of convenient graphs, you can see how quickly the charge drops in standby mode or when working in heavy applications, which helps to understand whether the problem is physical wear and tear or voracious software.

External signs of wear and physical examination

Software is good, but the physical state of the battery often says more than any number. Lithium polymer batteries tend to swell when they get older or damaged. It's because of the gases inside the sealed shell, and if you notice that the back of the smartphone is starting to move away or the screen is arching a little bit, that's an alarm bell.

A bloated battery is not just an inconvenience, it is a direct safety hazard, and the pressure inside the case can damage the display, the plumes and the motherboard itself, and in such cases, the device must be stopped immediately, and do not attempt to pierce the ballooned battery or put the phone under the press.

Also, note the idle discharge rate: If a phone lying on a table without use loses more than 5-10% of its charge overnight, it may indicate high internal cell resistance, a characteristic sign of aging battery chemistry when it can no longer efficiently store energy.

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Battery bloating is an irreversible physical process that cannot be fixed software-based, and the only solution is to replace the element immediately to avoid fire.

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