Redmi smartphone owners often face a situation where the device starts to discharge quickly or completely stops holding charge. In such cases, the first step to solving the problem is to replace the worn battery. One of the most popular and popular batteries on the market is the BM49, which has proven to be a reliable solution for restoring the autonomy of a number of devices of the popular brand.
However, before buying a new battery, it is critical to make sure it is compatible with your particular phone model. Using an incompatible battery can not only cause the gadget to malfunction, but also damage the motherboard. In this article, we will discuss in detail what models Xiaomi installs this type of battery, and how to properly replace it so as not to harm the device.
It can be difficult to understand the markings and specifications, especially given the abundance of smartphone modifications. We will help you navigate the technical nuances, explain the difference between the original and analog versions, and provide a step-by-step algorithm for actions. The BM49 code corresponds to a capacity of 4000 mAh and a voltage of 3.85 V, which is the standard for devices in the mid-range segment of previous years of release.
Specifications and features of the BM49
Battery battery BM49 It is a lithium polymer cell designed specifically for energy efficient smartphones. 4000 mAh, which provides a balance between the operating time and the dimensions of the case. 3.85 B, which is different from the standard 3.7-3.8 B, found in earlier models, so compatibility here plays a key role.
The battery is structurally equipped with a built-in protection controller that prevents overheating, overcharging and short circuiting. The protection board is integrated directly into the cell body, making the replacement safe when handled accurately. The dimensions of the battery allow it to fit tightly in the case without backlashes, providing reliable contact with the connector of the motherboard.
⚠️ Warning: Never use batteries with bloating or damaged shell. Attempting to charge or install such a cell may cause a fire or explosion inside the smartphone case.
When choosing a new battery, you should pay attention to the quality of the contacts and the presence of holograms from the manufacturer. Cheap copies often have less real capacity than claimed and degrade faster. The original Xiaomi BM49 is able to withstand about 500 full charging-discharge cycles with minimal loss of capacity, which is about 2-3 years of active use.
💡
Check the date of production on the battery label. If the battery is more than 2-3 years after release, even when sealed, its chemistry could degrade and it will not give up its full capacity.
Full list of compatible smartphone models
The main question that interests users: Xiaomi on what models puts the battery BM49? Most often this type of power is found in the series Redmi Note and some models Redmi with the letter "C" or "A." It is important to understand that externally similar phones can have different connectors of plumes, so you need to rely strictly on the compatibility list.
The most popular battery was used in the popular Redmi Note 3, which became a hit thanks to the metal body and good autonomy, and this battery is suitable for a number of devices built on a similar platform. Below is a list of the main models where the size is used. BM49:
- 📱 Redmi Note 3 (version 3GB/32GB, codename Kenzo/Kate)
- 📱 Redmi Note 3 Pro (Global Version)
- 📱 Redmi 3S / 3S Prime
- 📱 Redmi 4A (Some audits are required)
- 📱 Redmi 4X
It's worth noting that the Redmi 4A and some other models have different versions with BM40, BM44 and BM49 batteries. So the phone's visual similarity doesn't always guarantee compatibility. Always check the labeling of the old battery before ordering a new one. If your old battery says BM40, then the BM49 may not physically fit in thickness or connector.
How to distinguish the original from the fake
Xiaomi's spare parts market is full of low-quality copies.Distinguish the original battery BM49 There are a number of signs that can be easily checked when you receive the goods. First of all, pay attention to the packaging: original batteries often come in sealed bags with protective stickers and other products. QR-authentication.
The battery itself must have a clear, non-lubricating logo and technical information. On the original batteries, the text is laser-printed or with a quality print that is not erased by the finger. The weight of the battery also matters: the original weighs about 80-85 grams, whereas cheap copies can be noticeably lighter due to the use of less dense materials and less active substance.
| Sign. | Original BM49 | Quality copy | Cheap forgery |
|---|---|---|---|
| Weight. | ~82 grams | 75-80 grams | Less than 70 grams |
| Connector plume | Flexible, wide. | Hardy | Very thin, brittle. |
| Marking | Clear, laser-based. | Painted. | Lubricated or curved |
| Tension. | Strictly 3.85 V | 3.8 V V | 3.7 V V |
Another important thing is the status of the contacts on the plume, which is that the original has a golden hue and perfect geometry. If you see scratches, darkening or soldering marks on the new battery, it's a clear sign that the battery has been used or restored. The power controller on the original board is always covered with a black compound or has a specific chip labeling that meets the manufacturer's specifications.
⚠️ Warning: If the phone shows 1% charge after installing a new battery or cyclically restarts, it may be that the battery controller has not reset or the plume is damaged during installation.
Instructions for self-replacement of the battery
Replacing the battery in the Redmi Note 3 series and similar models requires care, but it is quite feasible at home with a minimum set of tools. You will need: a suction cup, a plastic spatula (mediator), a cross screwdriver and tweezers. Before starting work, be sure to turn off your smartphone.
The process begins with the removal of the back cover. Unlike modern monoblocks, in BM49 models, the cover is often removable, but can sit tightly on the latches. If the lid is not removable (as in some versions of the Redmi 4X), you will need to carefully peel off the perimeter with a warm-up hairdryer. After removing the lid, you need to unscrew all the screws that fix the plastic frame or the metal plate that covers the plumes.
☑️ Replacement tools
Then you have to turn off the battery plume from the motherboard, and you have to do this with a plastic tool to keep the contacts in check. The old battery is usually glued to a double-sided tape. You can use a suction cup to extract it, or you can gently tamper with the body with a spatula, trying not to damage the battery with a sharp object. You put the new battery in reverse order: sticking on a new tape, connecting the plume, assembling the case.
Sequence of action:
1. Turn off the device.
2. Remove the back cover.
3 Unscrew the screws of the protective plate.
4. Disconnect the battery plume.
5. Remove the old battery.
6. Stick the new BM49.
7. Connect the plume.
8. Collect the device and turn it on.After assembly, take your time to load the phone right away. It is recommended to charge it for 2-3 hours to calibrate the charge controller. If the phone is on and shows the correct percentage of charge that does not jump, then the replacement was successful. Otherwise, you may need to recheck the contacts or reset the battery statistics through the engineering menu.
What if the phone doesn’t turn on after replacement?
Typical problems after replacement and their solution
Even with the new BM49 battery installed correctly, users may experience software or hardware nuances, and one of the common problems is that the percentage of charge is misrepresented, the phone can show 100% and shut down 20% abruptly, or it can hang 1% for a long time before it turns off, and this is solved by calibration.
Calibration requires completely discharging the phone before it spontaneously shuts down. Then, without turning it on, charge to 100%. After reaching full charge, hold on to charging for another hour. Then turn on the phone (without removing it from charging), wait for loading and, if the percentage drops, recharge to 100%. Repeat the cycle 2-3 times. Calibration helps the controller remember the real limits of the capacity of the new battery.
Another problem is that the case is heated in the battery area, which may indicate high internal battery resistance or poor contact, and if the heating is accompanied by a rapid discharge in standby mode, you may have got a defective copy, and in such cases, you should not experiment, you should use the seller's warranty.
- 🔋 Phone discharges quickly - a defective battery or background processes are possible.
- 🔥 Heating in the battery area – poor contact or defect of the element.
- 📉 Charge percentage jumps – calibration or flashing is necessary.
⚠️ Warning: If you smell chemicals or see smoke from the speaker immediately after you install the battery, remove it immediately and stop using it.
Operational rules for extension of service life
To make the new Xiaomi BM49 battery last as long as possible, it is important to follow simple rules for the operation of lithium polymer cells. First of all, avoid deep discharge. Try to put your phone on charge when the energy level drops to 15-20%. Complete shutdown to zero is harmful to modern battery chemistry.
Temperature is also critical. Don't leave your smartphone in direct sunlight or in the cold. The optimal temperature for working and charging is from +10 to +25 degrees Celsius. Charging in the cold can lead to irreversible drops in capacity, and overheating accelerates the degradation of the electrolyte. Use only original or certified chargers with support for the right current.
💡
Compliance with temperature and the absence of deep discharges are two main factors that can extend the life of your BM49 battery by 30-40%.
Also worth mentioning is the impact of software: Background applications, constant network search in the area of poor reception and high screen brightness consume charge faster, forcing you to charge the device more often. Optimizing the MIUI settings, turning off unused communication modules and using energy saving mode will help reduce the number of charging cycles per day.