Modern smartphones like the Xiaomi Redmi 8 Pro are equipped with non-removable batteries, which makes it much more difficult to replace them yourself. However, over time, the capacity of the lithium polymer battery inevitably decreases, and the device begins to discharge or turn off faster in the cold. If you encounter such a problem, replacing the battery will be the only sure solution for extending the life of the gadget.
The dismantling process requires some preparation, precision and understanding of the internal structure of the device. Unlike the older models, you will have to work with adhesive layer and high-sensitivity plumes. Wrong actions can damage the display or motherboard, so it is important to strictly follow the algorithm of actions described in this article.
Before you start, make sure you have all the tools and spare battery, and it's important that you make sure to discharge your phone to 25 percent or lower before you start disassembling, because working with a fully charged battery increases the risk of fire in case of mechanical damage, and we'll look at all the steps from opening the case to the final system health check.
Tools and workplace preparation required
Replacing the battery properly is not possible without the appropriate tools. Use of inappropriate items such as knives or needles, is strongly discouraged, as they can damage the internal components or puncturing the battery itself. You will need a special kit for repairing mobile equipment, which can be purchased at any electronics store.
Special attention should be paid to cleanliness and lighting of the workplace. Small screws and plumes are easy to lose on a cluttered table, and poor light will lead to errors when disconnecting connectors. It is recommended to use an antistatic mat to eliminate the risk of static electricity, which is harmful to chips.
To successfully complete the task, prepare the following set:
- 🔥 A heat gun or dryer to soften the glue under the back cover.
- 🔧 Set of screwdrivers (star) T2, T3 cross-bow PH00).
- 💳 Plastic card or mediator for neat opening of the case.
- 🧲 Magnetic mat or sheet of paper with markup for sorting screws.
- 🧴 Isopropyl alcohol or special liquid for dissolving glue.
⚠️ Warning: Never use a metal tool to tamper with the battery.The metal can penetrate the cell shell, causing the battery to instantly ignite or explode.
Organize the space so that all tools are on hand.The Redmi 8 Pro takes 30 to 60 minutes to disassemble, and finding the right screwdriver in the middle of the job could cause accidental damage.
Primary disassembly of the body and access to the insides
The first step is to remove the tray for SIM-This is a mandatory procedure, because the presence of a tray can block the mechanism of opening the lid or cause it to break. Use a clip or a special needle key included in the package to press the hole next to the end of the device.
Next, heat the perimeter of the back cover. glue, fixing glass or plastic, melts at a temperature of about 80-90 degrees Celsius. evenly warm the edges of the smartphone for 2-3 minutes, constantly moving the hair dryer, so as not to overheat one point and not damage the OLED or IPS matrix of the display on the back side.
After heating, insert the suction cup into the bottom of the lid and pull up slightly, creating a gap. In the resulting gap, gently insert a mediator or plastic card. Move the tool along the perimeter, cutting the adhesive layer, but be careful in the area of the camera module and fingerprint scanner.
Inside, you'll see a plastic shield covering the main nodes, and it's attached to several screws of different sizes, and it's important to remember the location of each screw, because their lengths may vary, and use a magnetic mat or circuitry to avoid confusing the fasteners when you build them.
Disabling plumes and dismantling protective screens
When the bottom shield is removed, you can access the motherboard and the battery, and the first thing you need to do is to de-energize the device by disconnecting the battery connector, which is a critical step to prevent short circuits from continuing to work with other components.
Use a plastic blade to turn off the plume. Metal tools are also undesirable here because of the risk of damaging the contacts on the board. Carefully tuck the connector from the bottom up, trying not to put too much effort, as the connectors in Xiaomi are quite fragile.
Next, you remove the top protective plate, which often blocks access to the battery connector, which can be glued or fixed by screws, and if the plate is glued, it also needs to be slightly warmed up with a hairdryer before dismantling.
Now that access is open, you can move to extracting the power source itself. Notice the location of the plume that connects the battery to the board. It can pass under other elements, so you need to be very careful.
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If the connector of the plume sits very tightly, you can slightly poke it with a nail or a plastic spatula from different sides, but do not pull the plume itself - it can break.
The process of retrieving the old battery
The battery in the Redmi 8 Pro is fixed to a double-sided tape throughout the contact area with the frame. You can't just pull it out, you need to soften the glue. Use the hair dryer again, warming the back of the smartphone in the battery area for 3-5 minutes.
In some models, the manufacturer has provided special tongues to pull the battery. If they are not, or they broke, you will have to use a thin line, dental floss or a special plastic card.
Do not try to blow the battery with a screwdriver or knife from the ends. This is guaranteed to cause puncture and fire. If the battery does not respond, repeat the heating procedure. Patience is a key factor in success here.
| Parameter | Meaning | Note |
|---|---|---|
| Model battery model | BM4C / BN4C | Depends on the region of delivery |
| Capacity | 5,000 mAh | Nominal capacity |
| Type | Li-Po | Lithium-polymer |
| Tension. | 3.85 V | Typical value |
Once the adhesive layer has been overcome, carefully remove the old battery. Don't throw it into a regular trash can - old batteries require special disposal. Examine the compartment for any glue residue and remove it so that the new battery lays flat.
Installation of a new battery and assembly of the device
Before installing a new battery, clean the seat of old glue residues with alcohol or a special solvent. The surface should be clean and fat-free. If the new battery has adhesive tapes, use them. If not, apply a thin layer of special B-7000 glue around the perimeter.
Connect the new battery plume to the motherboard before you click, make sure the connector is flat and tight, and then you can temporarily turn on the device without sticking the lid to check whether it's working and charging.
☑️ Pre-assembly checks
If the phone is on and shows the correct charge level, you can start the final assembly. Lay the plumes carefully so that they are not clamped. Close the protective plates and twist all the screws into the appropriate holes.
Apply a new layer of glue to the frame of the case or use a pre-painted one on the new back cover (if you bought it as a whole), tightly press the lid around the perimeter and lock the device with rubber bands for 15-20 minutes to polymerize the glue.
Calibration and initial system start
Once assembled, the smartphone can behave in an unpredictable way, such as quickly discharge or showing the wrong percentage of charge. This is normal for a new battery, since the power controller has not yet calibrated to the new capacity. It requires a charging-discharge cycle.
Put the phone on charge when it's off to 100%. After reaching full charge, leave it for another hour. Then turn on the device and use it until it's completely discharged and turned off. Repeat the procedure 2-3 times for the indicator to work accurately.
Why does the phone warm up after being replaced?
Modern systems MIUI They automatically optimize power consumption. Give the device a couple of days to adapt. If the problem with fast discharge persists, check the usage statistics in the battery settings. → Consumption.
⚠️ Warning: If the phone stops turning on or charging after you've changed, don't panic. Check if the battery connector is tight. Often the problem is a low-pressed plume.
Frequently Asked Questions (FAQ)
Can I replace the battery without losing my warranty?
How long does it take to replace the battery with the Redmi 8 Pro?
Is a swelling battery dangerous to use?
Where to buy the original BM4C/BN4C battery?
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The main difficulty of replacement is the careful removal of the back cover without damaging the glass and the safe extraction of the battery without puncture.