Owning a Xiaomi smartphone is often associated with the user’s desire to maximize the battery life of the device. However, when the battery capacity begins to decline rapidly and the gadget itself is turned off by 20% of the charge, there is an urgent need to replace the battery. It is at this point that the owner faces the question: how to learn the model of the Xiaomi phone battery so as not to make a mistake when buying a new one? The market is oversaturated with fakes and low-quality copies, so accurate identification of the factory code becomes a critical task for successful repair.
Many users mistakenly believe that it is enough to remove the back cover to see the numbers you want, but modern smartphones have a sealed case. Fortunately, there are software methods and hidden engineering menus that allow you to access the specifications without opening the device. We will look at all the available methods, from simple commands in the “ring-box” to deep analysis of system logs, which will allow you to be sure of the compatibility of the new part.
It’s important to understand that different phone models, even those released in the same year, can come with different cell types. For example, Redmi Note’s lineup often features higher capacity variations that are physically different from the standard versions. A mismatched battery can not only fail to fit in the designated area, but also cause power controller malfunctions. So finding the exact item is the first and most important step before you start any manipulation of your smartphone’s hardware.
Use of the engineering menu and USSD-code
The fastest and safest way to get information about smartphone components is to use the built-in MIUI engineering menu. It is available on most devices of the brand and does not require the installation of third-party software. To enter, you need to open the standard Phone application and enter a special combination of characters. Immediately after entering the last sign, the menu will open automatically, giving access to hidden diagnostic sections.
The most versatile code for Xiaomi devices is ##6484## or its variation ##4636##. Once on the menu, you will need to find a section related to battery information. Usually called Battery info or Version. This is where the current status, charge level, voltage and most importantly, the code of the model installed cell is displayed. The interface may differ depending on the version of the MIUI firmware, but the data structure remains similar.
In some cases, especially on newer models with unauthorized access protection, the direct output of the model code can be hidden or replaced with a common identifier. If standard codes do not work, try entering ##3646633#. This code opens an extended engineering menu where more detailed information can be found in the Hardware Testing → Power → Battery Test tab. Please note that some global firmware versions may restrict access to these codes by the carrier.
Note that the engineering menu shows the data that the Battery Management System (BMS) controller reads. If the battery has already been replaced with an unoriginal or overstuffed one, the information displayed may not correspond to reality, in which case the software methods fail, and you have to resort to a physical examination or a deeper analysis of the system.
Analysis of information through diagnostic applications
If you don't have access to the engineering menu or if you don't think the data is complete enough, you'll find special applications from the Google Play Store that can read data from Android system files and interpret it in a user-friendly way. One of the most reliable tools is AIDA64, which provides comprehensive information about the hardware of the device.
Once AIDA64 is installed and started, you need to go to Battery, where you'll see not only the current charge and temperature, but also the Model or Technology field. Often this section is the factory code, usually starting with the letters BM (e.g. BM3E, BN46), and a useful application is the CPU-Z, which shows similar data in the Battery tab, sometimes even providing information about the cell manufacturer.
Another powerful tool is AccuBattery, which, while its primary function is to monitor battery health and wear rate, can also display manufacturer-declared capacity and model ID in the settings or details section, but it's worth remembering that these applications work with data provided by the operating system. If the system file with the battery configuration is damaged or changed, applications may show incorrect information.
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To get the most accurate data through the apps, give them all the permissions requested and run the scan with the charger connected – this will update some hidden settings.
The advantage of using third-party software is the ability to save a report or take a screenshot with full information about the status of the battery cell. This is especially useful if you plan to order a part online and want to check the characteristics against the description of the seller. In addition, such applications often show the real capacity against the passport, which helps to assess the degree of degradation.
Decoding of factory markings and codes
When you finally get the model code (like the BM4C or BN41), it's important to interpret it correctly.The Xiaomi and Redmi battery codes have their own logic. They usually consist of two letters and two digits (or letters and numbers). BM letters often denote standard batteries for smartphones with removable or non-removable lids, while BNs may indicate models with increased energy density or a specific series.
The digital part of the code indicates a generation or a specific modification for a particular line of phones. For example, the BN46 battery was installed in the Redmi Note 8 Pro, and the BM3F was installed in the Xiaomi Mi 4i. If you know the exact code, you can search for it in search engines or on the sites of spare parts suppliers. It is important to look for a complete match, since batteries with similar codes (different by one letter) can have different plume locations or connectors.
Below is a table matching popular battery codes with the phone models they are designed for, which will help you quickly navigate if you find the code on an old battery or in the system.
| Battery model code | Compatible phone models | Typical container | Features |
|---|---|---|---|
| BN46 | Redmi Note 8 Pro | 4500mAh | High density, non-removable |
| BM3E | Xiaomi Mi 5 / Mi 5s | 3,000 mAh | Compact form factor |
| BN41 | Redmi Note 4 / Note 4X | 4100mAh | One of the most massive models |
| BM39 | Xiaomi Mi 4 | 3080mAh | Removable construction (rareness) |
| BN59 | Redmi 9 / 9A / 9C | 5,000 mAh | Increased cycle resource |
When searching by code, look at the region of production. Sometimes you see batteries with the same code but released for different markets (China, Global Version, India) and they may differ slightly in the calibration of the controller. Using the original code ensures that the geometry of the case and the position of the contacts will match perfectly with your device, eliminating the problems with closing the lid.
Physical inspection and inspection of the plume
The most reliable, but also the most time-consuming way to know a model is by physical examination, which is necessary if the phone is not turning on, the screen is broken, or the software methods are not working, which requires gently opening the case of the smartphone, heating it around the perimeter and peeling off the back panel, and you need to do this extremely carefully, using suction cups and plastic blades, so as not to damage the plumes of the display.
Once you get access to the insides, you unscrew the protective plate that covers the battery connector. And if you carefully unplug the plume, you can remove the battery. On the back, on the white or black label, there's always a marking on it. Look for a large barcode and Model or just a set of letters and numbers in the format described above. And it also indicates the date of production, which is useful for estimating the age of the cell.
☑️ Autopsy battery check
Attention: ⚠️ If you see that the battery is swelling (became like a pillow), do not puncture it or try to put it back into the phone. This can lead to fire. These batteries require special recycling. If they have blackened or oxidized, it can cause charging problems, even if the cell itself is in good working order.
Often present on the label. QR-It can be thought of as another smartphone's camera, which sometimes leads to a technical specification page, although more often it's just the manufacturer's internal code to track the batch. 4-6 symbolism.
Hidden system files and ADB-team
For advanced users with access to debugging mode USB (USB Debugging, you can request information directly from the system through the computer, and this is especially true if the phone screen is partially out of order, but the system responds to commands. ADB on a PC and connect a smartphone with a cable.
In the computer's command line, after you input the adb device command to check the connection, you can use the command to read system properties.
adb shell dumpsys batteryThis command will give you a lot of data. Look for model or technology strings. However, you can get a deeper level of information by querying properties directly from Android configuration files, if the device has root rights, or through specific queries to Battery Properties. Adb shell cat team /sys/class/power_supply/battery/property_name (where property_name You have to guess, it's often model_name) can return the desired value.
Another option is to use a logcat logger. When you plug in a charger, the system generates many logs. When you run an adb logcat | grep-i battery, you can see the system's power status messages in real time. Among the hundreds of lines, the exact model name sometimes slips through, which the controller tells the kernel of the system when initialized.
What if the ADB can’t see the phone?
Common mistakes in selection and purchase
The most common mistake is to buy a battery solely by the name of a phone model. Marketplace vendors often write in the title "Battery for Redmi Note 9", without specifying that there are different revisions of this model (Global, NFC, India) that can have different batteries. Always check the model code found by software or on an old battery with the code on the product.
The second mistake is ignoring the thickness of the battery, in pursuit of more capacity (e.g., the battery, 5000 mach 4000 mAh) users buy reinforced batteries. They can be on 1-2 In Xiaomi's sealed cases, this will cause the back cover to simply not close or to press on the display, creating rainbow spots and eventually breaking it.
⚠️ Warning: Buying cheap copies without a protective fee (BMS) Or with a poor-quality protection board, it could cause the power controller on the phone's motherboard to fail. Xiaomi's original batteries have a complex overheating and overdischarge protection scheme.
Also beware of batteries with regurgitated labels. There are many refurbished batteries on the market, where a new but cheap cell is inserted into the old case, and the label is replaced with the original one. Signs of counterfeiting can be: blurred font, no holograms (on some models), weight mismatch (lith has a certain density), and, of course, rapid loss of capacity in the first weeks of use.
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The key to success is the complete matching of the model's alphanumeric code (e.g. BN46) and the physical dimensions of the plume. Don't rely on phone name compatibility alone.