Redmi 4 series mobile devices have earned a reputation as long-lived consumers in the low-end electronics market. However, even the best-quality lithium-polymer cell loses its capacity over time, losing its charge as it did in the first months of operation. If your smartphone runs out in a couple of hours or suddenly turns off at 20-30% charge, this is a sure sign that the resource of the chemical source of current is exhausted.
Self-replacement of the battery in Xiaomi Redmi 4 is a realistic task for a user with minimal skills in working with small electronics. Unlike many modern flagships with fixed structures and waterproof housings, this model allows a relatively affordable maintenance procedure.
In this guide, we will discuss in detail the process of selecting a compatible battery, preparing the workplace and sequentially disassembling the case. It is important to understand that any manipulation of the internal components of the gadget requires accuracy and compliance with safety. Xiaomi Redmi 4 has its own design features, ignoring which can damage the plumes or plastic mounts.
Diagnosis of the battery condition and selection of components
Before the physical intervention is initiated, it is necessary to make sure that the problem lies in the wear of the battery, and not in the software failure or malfunction of the power controller ##6485## in the dialing field, allow the current capacity and health status of the battery. MB_06 shows the status of "Good", but the operating time is still critically short, so the physical wear of the plate is already great.
The spare parts market is full of offers, but the quality of products can be radically different: the original battery is labeled BM46 and has a capacity of 4100 mAh. When buying analogues, you should pay attention to the presence of a protective chip (BMS) that prevents overheating and overcharging. Cheap copies often do not have proper protection, which creates a risk of bloating or even fire.
How to distinguish a quality battery from a fake?
When choosing a new battery, consider the following criteria:
- 🔋 Capacity: Must conform to the declared (4100 mAh), deviations greater than 5% are not allowed.
- 🛡️ Protection: availability of a microcontroller protection against short circuit and overheating.
- 📏 Dimensions: the thickness of the element should not exceed the factory, otherwise the back cover will not close.
- 🏷️ Labeling: clear fonts and no grammatical errors in the brand name.
Ignoring the quality of components can lead to the fact that after a month you have to repeat the repair procedure. The savings on the battery often turn into the purchase of a new device, since a low-quality element can damage the charging connector or motherboard with voltage surges.
Tools and workplace preparation required
The success of the operation depends on preparation. You will need a specialized set of tools, since ordinary household appliances can damage fragile components. The main tool for opening the case is a suction cup and a thin plastic blade (mediator). The use of metal objects at this stage is strictly prohibited, since there is a high risk of damage to the display glass or metal frame.
To work with internal screws you will need a set of precision screwdrivers. Xiaomi Redmi 4 uses screws of different types: cross (PH000) and, in some versions, screws with an asterisk (Torx T2 or T3). Also indispensable assistant will be tweezers with curved ends for careful extraction of plumes and plastic plugs.
☑️ Battery replacement tools
Organize the workspace correctly:
- 💡 Lighting: Bright light is needed to see small screws and connectors.
- 🧲 Magnetic mat: screws are better to unfold in order of their twisting, so as not to confuse the length.
- 🧤 Antistatic: It is advisable to use an antistatic bracelet or periodically touch a grounded object.
Before starting work, be sure to turn off your smartphone. Even when turned off, the board may still have residual voltage, so try not to touch the contacts of the connectors with your fingers. If the battery is swollen, be especially careful - damage to its shell can lead to ignition of the electrolyte.
The process of disassembling the body Xiaomi Redmi 4
The Redmi 4 design involves disassembly from the display side, since the back cover is a non-removable metal plate integrated into the body. This makes the process slightly more complex compared to models with removable rears. SIM-cards and memory cards to provide access to hidden screws.
At the bottom of the device, next to the microUSB connector, there are two screws, which you need to unscrew first. Then use the suction cup at the bottom of the screen to slightly lift the display module. Insert a plastic blade carefully into the gap and start walking around the perimeter, snapping the plastic latches.
⚠️ Attention: Don't put too much effort into snapping the case. Plastic in budget models can be brittle, and a sudden movement will lead to cracks in the frame or chips on the glass.
Once all the latches around the perimeter are free, take your time to open the phone completely. The display module is connected to the motherboard with a wide plume. A sharp jerk is guaranteed to tear it, which will require replacing the expensive screen. First, carefully lift the module and inspect the connection area.
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To facilitate the process of snapping latches, you can slightly warm the perimeter of the screen with a hair dryer to a temperature of 40-50 degrees. The plastic will become more elastic, and the risk of breaking the clip will decrease.
Disconnecting plumes and removing the old battery
When you get access to the insides, you'll see a metal screen that covers the main connectors, and depending on the board revision, that screen can be mounted on screws or just snapped, and you'll often need to twist a few screws in the center and in the camera area.
The next critical step is to turn off the plumes, and the first thing that's always going to be done is to disconnect the battery connector, and only after the board has been de-energized can you safely turn off the display plume and the touchscreen, and then use a plastic blade or nail to pull the connector up, but don't pull the wires.
The battery in Redmi 4 is glued to the body with double-sided tape to extract it:
- Find special tongues for pulling (if they are preserved).
- If there are no tongues, carefully tuck the edge of the battery with a plastic card.
- Use isopropyl alcohol by dripping a couple of drops under the battery to dissolve the glue.
Under no circumstances should you use metal tools to pick the battery. A puncture of the lithium cell shell causes an instant chemical reaction to release heat and smoke. If the battery sits very tightly, it is better to spend time gently loosening than risking the integrity of the device.
| Parameter | Original (BM46) | Quality analogue | Cheap copy |
|---|---|---|---|
| Capacity | 4100mAh | 4000-4100 mic | 2500-3000 mAh |
| Tension. | 3.85 In | 3.85 In | 3.7-3.8 Included |
| Weight. | ~82g | ~80g | ~60-70g |
| Term of service | 500+ cycles | 300-400 cycles | 50-100 cycles |
Installation of a new battery and assembly
Before installing a new battery, clear the seat of the residue of old glue.The surface should be flat and clean so that the new battery will lie tight and not hang inside the case. Use a new double-sided tape, which often comes complete with the battery, or apply a thin layer of special B-7000 glue to fix it.
Connect the battery connector to the motherboard before the characteristic click. Make sure the connector is flat and tight. Only then you can plug the display plume in, and make sure that there are no cracks on the plumes and that they are under the screws when you try them on.
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The order of connection is critical: first the battery, then the display, and reverse sequence when disconnected is also necessary to prevent short circuit.
Check the device before the final assembly. Press the power button. If the screen catches fire and the phone reacts to the touch, it's a success. If the screen is black, check the density of the plume of the display, often you need to reconnect it.
Twirl all the screws of the metal screen protection. Make sure that no screw is left over. Then gently snap the display module around the perimeter, starting at the top and gradually descending to the charging connector. Lastly, twist the two lower screws and install the tray. SIM-map.
Primary charging and calibration
After the battery is replaced, the system may not correctly display the percentage of charge, since the power controller has not yet “acquainted” with the new battery.
The calibration process is as follows:
- 📉 Discharge the phone until it is completely turned off (0%).
- 🔌 Connect the charger and charge up to 100%, not including the phone.
- 🔄 After the 100% hold on to the charger. 1-2 hour.
- 📲 Turn on your phone and check the charge level. If it's less than 100%, charge it again.
It is recommended to perform 2-3 full charge-discharge cycles in normal use, this will help to align the indicator readings and prolong the life of the new cell. In the first days of use, monitor the heating temperature of the case - the new battery should not warm much under moderate load.
⚠️ Warning: If the phone continues to discharge rapidly after replacement or warms up in the lower part (where the battery is located), immediately stop using.This may indicate a battery defect or a problem with the charge controller on the board.