Xiaomi’s smartphones and its sub-brand Redmi are well-deservedly popular for their excellent value for money. However, over time, even the most reliable lithium-polymer battery starts to degrade, losing its original capacity. Owners often face the need to replace this component, but do not know what part to look for in the catalogues of suppliers.
Knowing the exact model of a battery is not only essential to buying the original part, but also to authenticate the device you plan to buy with your hands.The market is full of fakes that install cheap counterparts with understated performance. Knowing the labeling will allow you to avoid disappointment and protect your device from a potentially dangerous low-quality battery.
In this article, we will take a detailed look at the software and physical methods of identifying a battery, and we will look at hidden engineering menus, specialized applications and visual features that will help you get comprehensive information about the condition and type of your battery without the need to disassemble the case.
Using engineering code for diagnostics
The fastest and most proven way to access technical information about the battery is to use a special engineering menu. The MIUI shell on which Redmi smartphones are based has a hidden section for testing the equipment. To activate it, you need to open the standard Phone application and dial the symbol combination # # # # # #6485##.
After entering the last star on the screen, the window will automatically open. MIUI Battery Info. The interface may look intimidating because of the abundance of numbers and acronyms, but we're interested in specific lines. MB_06 — It shows the battery health status (Good, Bad or a specific percentage) and the line MB_00, which shows the current percentage of charge.
But the most important information is the model and the actual capacity. MB_01 (sometimes MB_0A depending on the version of Android, where the code of the model is specified, for example, BM3E or BN46. Also pay attention to the parameters. MF_02 (nominal capacity) and MF_05 (The actual capacity in mAh is the current capacity, and the comparison of these two values will give you an accurate understanding of the wear and tear.
What if the code doesn't work?
⚠️ Warning: Do not try to change the values in the engineering menu or reset battery statistics without understanding the consequences. Incorrect interference with system calibration data can lead to incorrect display of charge percentages.
- 📱 The code works on most Redmi Note and Redmi devices with a digital index.
- 🔋 Parameter MF_05 It shows real wear and tear, not the manufacturer's declared.
- ⚙️ Access to the menu does not require root rights and is safe for guarantee.
- 📉 If MF_05 less MF_02, battery-change.
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Engineering code ##6485## is the most reliable software method for obtaining an accurate model and current capacity without installing third-party software.
Analysis of information through system settings
If you find the code too complicated or not working, you can try to find the information in the standard operating system interface, but manufacturers often hide the detail, leaving only the general data. MIUI HyperOS can be used to find useful information.
Go to Settings → About Phone → All specs → Battery. This can show the type of battery (usually Li-Polymer) and its rated capacity. Unfortunately, the specific model code (such as BN43) is rare in this section, as manufacturers consider this technical information for service centers.
A more efficient way is to check the battery status through the Safety menu.The standard Safety app (green zipper icon) often has a Battery or Status section. By clicking on the settings gear in this section, you can see more detailed charging cycle statistics and current status, although the model can still be hidden.
It is worth noting that system settings often show calculation data that may not match the physical parameters of the installed element, especially if the phone has previously been opened, so this method is more suitable for general evaluation than for accurate identification of the spare part before purchase.
Application of third-party applications for Android
When built-in tools are scarce, specialized tools come to the rescue from the Google Play Store, which read data directly from the power controller and provide it in a convenient way. One of the most popular and reliable tools is the AccuBattery app.
Once you install and launch AccuBattery, go to the Health tab, and the app will show you the estimated capacity, which is calculated from the analysis of charging cycles. Although it doesn't always show the alphanumeric code of the model (such as the BM39), it's ideal for estimating the actual state of the battery in milliamp hours.
Another powerful tool is the Phone Info SAM or CPU-Z application. Under the "Device" or "Battery" section, these programs can often pull out deeper system logs, including the name of the battery model if it is written in the firmware of the device. In the CPU-Z, you need to open the "Battery" tab and search for the "Technology" and "Model" string.
⚠️ Warning: Third-party applications don't have access to the physical volume sensor, they read the data that the controller is broadcasting. If the controller is "cheated" or overfiltered, the applications will also show incorrect information.
- 📲 AccuBattery requires multiple charging cycles to calibrate data.
- 📊 CPU-Z Provides voltage and temperature information in real time.
- 🛡️ Applications are secure and do not require superuser rights.
- 📉 The error of the program methods can be up to 5-10%.
Physical marking and visual inspection
The most reliable way to guarantee 100% accuracy is to physically inspect the battery, and no software reset or virus can change the label printed on the factory inside the case, and this requires carefully removing the back cover of the smartphone.
In modern Redmi models, the back cover is often glued, so you'll need a hair dryer to warm up the perimeter and suction cup, or a thin plastic card. Once you remove the lid and unscrew the protective strip of the plume, you'll see the battery itself. On its front side, there's always a large print marking.
Look for a string that starts with BM or BN, followed by numbers (e.g. BM46, BN41). This is the model you want. Also next to it is the capacity (e.g. 4000mAh), the voltage (3.85V) and the date of manufacture. Compare this data with the information on the Internet to make sure the part is original.
☑️ Checking the battery during disassembly
Pay attention to the appearance of the battery. The original always has a good print, clear seams and no traces of glue on the cell itself (the glue should only be on the frame or body). If you see bloating, it is a sign of a chemical reaction inside, and you absolutely can not use such a device.
Table of popular models of batteries Redmi
To make it easier to find, we’ve compiled a table matching popular Xiaomi Redmi smartphones and their batteries, which will help you quickly navigate if you only know the name of the phone, but do not know the code of the part.
| Smartphone model | Battery code. | Nominal capacity | Type |
|---|---|---|---|
| Redmi Note 4 / 4X | BN41 | 4100 mAh | Li-Polymer |
| Redmi Note 8 Pro | BN4H | 4500 mAh | Li-Polymer |
| Redmi 9 / 9A / 9C | BM3S | 5000 mAh | Li-Polymer |
| Redmi Note 10 Pro | BM4H | 5020 mAh | Li-Polymer |
| Xiaomi Mi A2 Lite | BM3E | 4000 mAh | Li-Polymer |
It is important to understand that within the same phone model (for example, Redmi Note 8) in different regions or in different years of release could be used batteries from different manufacturers (ATL, Desay, Sunwoda), but the model code (BN4H) remained the same for compatibility.
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When buying a new battery, pay attention not only to the model code, but also to the date of production. Lithium batteries age even on the shelf, so the battery, which has been lying for 3 years, will have a reduced life.
How to distinguish the original from the fake marking
The spare parts market is flooded with copies that can look very similar to the originals, but if you look closely at the labeling, you can find differences. Xiaomi's original batteries have a holographic sticker with a different design. QR-code that can be checked on the official website.
The print quality on the original is always perfect: the font is clear, not lubricated, the colors correspond to the corporate style. On forgeries, you often find spelling errors in the English text, blurred logos or the absence of a protective hologram.
Another sign is weight. The original battery always weighs as much as the specification says. Cheap copies are often lighter because of the use of less dense materials and less active substance. If you have an accurate scale, weigh the battery and compare it with data from datashit.
⚠️ Warning: Using unoriginal batteries can cause the power controller to fail quickly or even the device to catch fire.The battery savings are not worth the risk of losing an expensive smartphone.
- 🏷️ Presence of a protective hologram with QR-code-wise.
- ✍️ The font on the original is clear, without spreading the paint.
- ⚖️ The weight must be in accordance with the declared characteristics.
- 🔌 Contacts should be golden, without oxidation and scratches.