Finding the exact battery labeling is often the first task of a smartphone owner facing rapid battery discharge or bloating.The BM-46 code is one of the most common identifiers in the Chinese manufacturer's ecosystem, but it doesn't always unequivocally point to a particular phone model without additional context.The fact is that the company's engineers often use a single power platform for multiple device modifications released during the time period.
In this article, we will discuss in detail what devices this power cell is designed for, and how to make sure you don’t go wrong when ordering a spare part. Compatibility is a critical parameter, because even a minimal difference in the geometry of the plume or the location of the contacts can make installation impossible or, worse, damage the charge controller. Understanding which model is hidden behind the BM-46 label will help you save time and avoid buying the wrong component.
We will look at the technical details, visual verification methods and software methods for determining the current battery, and also touch upon safety issues, because working with lithium polymer energy sources requires compliance with certain rules. The BM-46 code corresponds to the batteries for the Redmi Note 4 (Global version) and Redmi Note 4X. This is a key difference that is often overlooked, confusing them with the version for the Indian market (BM-45).
Device identification and compatibility
The main difficulty is that the popular Redmi Note 4 series has several regional versions that are almost identical in appearance, but can differ significantly inside.The BM-46 battery is designed specifically for the global version of the smartphone, known as the Redmi Note 4 Global, based on the MediaTek Helio X20 processor. However, the same battery is physically and electrically compatible with the Redmi Note 4X version, which runs on the Qualcomm Snapdragon 625 chipset.
It is important not to confuse this model with the Redmi Note 4 for the Indian market (India version), which is also built on the Snapdragon, but uses a battery labeled BM-45. Despite the similar names, the BM-45 and BM-46 batteries have different thickness and location of the plume, so they are not interchangeable. If you try to install the BM-46 in a device that requires a BM-45, the lid simply will not close, or the connector will not fit into the motherboard connector.
To determine compatibility accurately, remove the back cover of the device and visually inspect the sticker on the battery itself before buying or replacing it, and use system information if the phone is still turning on.
- 📱 Xiaomi Redmi Note 4 (Global Version, MediaTek)
- 📱 Xiaomi Redmi Note 4X (Qualcomm Snapdragon)
- 📱 Some modifications of the Redmi Note 4 Pro (Chinese version)
When ordering a spare part, always check the device region from the seller or check the model code in the system settings. The About section often includes full labeling, such as the "Redmi Note 4X" or the code name "mido" for the Snapdragon version. Make sure you don't buy a battery for the "Redmi Note 4 Prime" or other variations unless you're sure they're compatible with the BM-46.
Technical characteristics of the BM-46 battery
Energy capacity is one of the main parameters that users pay attention to. For the BM-46 model, the declared rated capacity is 4100 mAh (typical capacity can vary to 4200 mAh depending on the batch), This provides a smartphone with an energy-efficient Snapdragon 625 processor up to two days of battery life in mixed use.
The battery voltage is standardized at 3.85 volts, which is typical of lithium polymer batteries of the period. The energy density in this form factor is high enough to keep the device thin. Li-Po technology provides no memory effect and relatively low self-discharge during storage.
| Parameter | Meaning | Note |
|---|---|---|
| Model | BM-46 | Primary identifier |
| Type | Li-Polymer | Lithium-polymer |
| Capacity (nom.) | 4100mAh | Min 4000mAh |
| Tension. | 3.85 In | Standard. |
| Energy | 15.78 Wht | Calculated. |
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Pay attention to the production date indicated on the battery plume or body, and the optimal battery age is up to 1 year from release, as lithium chemistry degrades even when stored.
Importantly, the actual capacity of a new battery may be slightly different from the 3-5% margin of error claimed, which is a normal manufacturing tolerance, but if you see a significant variability or a battery run out in a couple of hours, you probably have a low-quality copy or a refurbished cell.
Differences between BM-46 and BM-45 and other modifications
The difference between the BM-45 and the BM-46 is one of the most common issues in Xiaomi’s home communities. These batteries may look similar, but their design features are different. The BM-45 is designed for the Redmi Note 4 (India) and has different thicknesses and contact group locations. Trying to install the BM-46 instead of the BM-45 will result in the battery simply not falling into place due to the thickening in the plume.
There are also batteries with BM-44 or BM-47 codes that have been used in other Redmi models, such as the BM-44, which was often found in earlier versions or other series. The confusion arises from similar numbering, but the physical shape of the case (plastic packaging of the cell) is the decisive factor. Always compare the shape of the "native" battery with the new one, even if the seller assures of versatility.
⚠️ Warning: Never try to force the battery to run. BM-46 c. the enclosure BM-45. This can cause mechanical damage to internal components, battery puncture and fire.
Also worth mentioning is the Battery Management System (BMS) on the battery board. The original BM-46 correctly interacts with the smartphone's power controller to display the correct percentage of charge. Cheap alternatives often use simplified boards that can show incorrect data or shut down under load.
How to check the originality of the chip?
Instructions for safe replacement of the battery
Replacing the power supply in the Redmi Note 4/4X is a moderately complex procedure that requires accuracy and a minimum set of tools. The smartphone body has no mechanical latches and is assembled on an adhesive compound, so the first step should always be to heat the back cover. Use a hair dryer or special heating pad, warming the perimeter of the device to a temperature of 60-70 degrees Celsius for 2-3 minutes.
Once the glue is softened, gently apply the lid to a plastic blade or mediator as you walk around the perimeter. Do not use metal tools like knives or blades, as there is a high risk of damaging the glass or hurting. When the lid is removed, you will see a metal plate covering the battery plume and display sockets, which is screwed up with several screwdrivers that need to be twisted out with a cross screwdriver.
☑️ Replacement tools
After removing the metal shield, disconnect the battery plume from the motherboard. Removing the battery itself often requires pulling on special tongues, if any, or gently tweaking it with a plastic card. The glue under the battery can also be durable, so it is allowed to easily heat the back of the smartphone in the battery area.
Sequence of action:
1. Heating the back cover.
2 Removal of the back cover.
3. twisting of the screws of the metal plate.
4. Disable battery plume.
5. Removing the old battery.
Installation of a new BM-46 battery.
7. Connecting the plume and assembly in reverse order.When installing a new BM-46 battery, make sure the connector snaps to the characteristic clicks. Before final assembly and twisting the screws, it is recommended to turn on the phone and check the operability of the sensor, display and charging. If everything is functioning correctly, apply a new layer of glue or use double-sided tape to fix the cover.
Diagnostics of condition and calibration
After installing a new battery or if you suspect that the old one is wearing out, it is useful to conduct a diagnosis. Xiaomi smartphones have a built-in engineering menu that allows you to check the status of the battery ##6485##. In the menu you are interested in the parameters. MB_06 (battery status; and MB_00 (charge-rate).
If the phone shows that the battery is "Good" but is rapidly discharged, calibration may be required. This process helps the system correctly determine the boundaries of full charge and full discharge. To calibrate completely discharge the phone before turning off, then charge it when off to 100%. After reaching 100%, hold on charging for another 1-2 hours.
- 🔋 Discharge the device to 0% (until completely switched off).
- 🔌 Charge to 100% in the off state.
- ⏳ Leave it on the charger for another one. 1-2 half-hour.
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The calibration procedure does not restore the physical capacity of the worn-out battery, but allows the system to correctly display the remaining percentage of charge.
It’s also worth checking the battery usage statistics in the Settings → Battery → Statistics menu. If you see a particular application consuming an abnormally high amount of power even in the background, the problem may not be in the hardware, but in the software, in which case resetting or removing a problem application helps.
Frequent problems and methods of their solution
Owners of BM-46 batteries can face a number of common problems, one of the most common is that the phone doesn't see charging or shows charging, but the percentage doesn't rise, often due to oxidation of contacts in the charging connector (USB) or damage to the charging plume, which in the Redmi Note 4 is combined with the headphone jack.
Another problem is that you quickly discharge after replacing, and if you installed a new battery and it still holds a bad charge, you may have been sold a poor-quality copy. The market is saturated with fakes that are visually indistinguishable from the original, but have a capacity that is 2-3 times smaller than the declared one, and you can check this with the help of AccuBattery, which analyzes the actual capacity during use.
⚠️ Attention: Battery bloating is a critical sign of malfunction. BM-46 It is strictly prohibited, as it can cause damage to the display (extrusion) or fire.
If the phone is cyclically restarted (bootloop) immediately after the battery is connected, check the density of the connector. Sometimes it helps to reconnect the plume and clean the contacts with alcohol. In rare cases, the problem may lie in the power controller on the motherboard, especially if the device has previously been hit or moisture.
What if the phone doesn’t turn on after replacement?
Operational rules for extension of service life
To make the new BM-46 battery last as long as possible, you need to follow the rules of operation of lithium polymer cells. The main enemy of such batteries is overheating and deep discharge. Try not to leave the phone in the sun, on the dashboard of the car or near heat sources. High temperatures accelerate the chemical degradation of the electrolyte.
The optimal charge range for long-term storage and use is from 20% to 80%. Constant charging to 100% and discharge to 0% create excess voltage on the cells. Modern smartphones have controllers that cut off charge, but maintaining the level in average values favors the chemistry of the battery.
Use only certified chargers and cables. Cheap power supplies can produce unstable voltage or current, causing the charge controller and battery itself to overheat. Xiaomi's original Quick Charge-enabled charger pairs with the BM-46 controller most efficiently and safely.
- 🌡️ Avoid overheating the device while charging (remove the case).
- 🔋 Do not allow a full discharge to zero regularly.
- 🔌 Use quality cables and power supplies.
Keeping these simple guidelines in mind will keep you from having to deal with the issue of autonomy for a long time, and remember that the battery life is limited to the number of charge-discharge cycles (usually 500-800 full cycles), and you can’t stop aging completely, but you can slow it down significantly.