Xiaomi smartphone owners often face a situation where their favorite device stops holding charge.This is a natural process of wear and tear of lithium-polymer batteries, which usually occurs after 500-800 full charging cycles. If your phone runs out in a couple of hours or turns off in the cold, it's time to think about replacing the power unit.
Replacing a power source on your own saves you a lot of money compared to going to an authorized service center, but it requires care, special tools, and an understanding of the device's internals, and doing the wrong thing can damage the display plumes or even cause fire.
In this article, we will discuss in detail the procedure for replacing the battery on Redmi, Poco and Mi smartphones. You will learn what tools you will need, how to safely remove the old battery and what to look for when installing a new one. Compliance with all the steps of the instructions minimizes risks and returns your device to factory autonomy.
Diagnosis of battery status
Before you disassemble the phone, you need to make sure that the problem lies in the wear of the chemical element. Sometimes rapid discharge is caused by software failures or background processes. You can check the real capacity through the engineering menu or special applications.
The most accurate method of diagnosis is to use the command line ##6485##. In the menu, find the parameters. MB_06 (state of health and MB_00 (If the health bar says "Good" but the phone is not working well, it may be the calibration.
Physical signs also speak volumes about the need to replace, and the swelling of the body is a critical signal, in which case it is life-threatening to operate the device, as a damaged battery can ignite or explode when mechanically exposed.
- 📉 A sharp drop in percentage charge (for example, from 40% to 5% in 10 minutes).
- 🔋 The phone turns off when the charge is above 15%.
- 📱 The back cover or screen began to move away from the body.
- 🔥 The device is very warm even in standby mode.
If you see at least two of these symptoms, replacement is inevitable, and ignoring the problem can cause the motherboard's power controller to fail, making repairs economically inefficient.
Tools and workplace preparation required
You can't have a good repair without the right tools, and if you try to open a modern smartphone with a knife or a screwdriver from a kitchen kit, you'll have chipped things on the body and damaged the internal components, and you'll need a specialty kit to open the machine.
The main difficulty in modern Xiaomi models is the adhesive base on which the back cover is held. To soften it will require a heat source. Household hair dryer is not suitable here, as it does not give the desired concentration of temperature at one point.
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Use medical alcohol or a special liquid B-7000 to dissolve the glue – this will greatly simplify the opening of the case without damage.
Prepare the container for small screws, as their size may vary. Losing at least one fastener can cause parts to rattle inside the case or disrupt the connector press.
- 🌡️ Thermophen or hot water heater for softening glue.
- 🔧 Set of screwdrivers (cross-haired) PH000, Torx T4/T5).
- 🎴 Plastic blades and mediators for opening.
- 🧲 Magnetic screw-sorting mat.
- 🧤 Antistatic gloves to protect electronics.
It is also recommended to have a suction cup on hand, which helps create an initial gap between the lid and the frame, where a plastic blade is then inserted, and it is strictly forbidden to use metal tools to pick inside the case.
The process of disassembling the Xiaomi smartphone
The first step is always to shut down the device completely. Working with the electronics under voltage can cause a short circuit. SIM-cards to facilitate access to the insides and avoid accidental damage to the slot.
Heat the perimeter of the back cover to 80-90 degrees Celsius. Keep the hair dryer at a distance of 3-5 cm for 2-3 minutes. Don't overheat one point, move the device evenly. The glue should become elastic, but not melt completely.
☑️ Preparation for disassembly
Apply a suction cup to the bottom of the lid and pull up slightly while inserting a plastic blade into the resulting slit. Driving the tool along the perimeter, cutting the adhesive layer. Move slowly so as not to damage the fingerprint scanner plume if it is glued to the lid.
Once the back panel is removed, you'll have access to the screws of the lower clamping bar. Unscrew all visible fasteners. Note that in some models, the screws may be hidden under stickers or plugs.
⚠️ Warning: Don't put too much effort into removing the lid. If it doesn't lend itself, the glue isn't warmed enough, and reheating is safer than the risk of breaking the glass.
Replacement of the battery and disconnection of plumes
Once the safety bar is removed, the main connectors will be accessed, and the first step is to disconnect the battery plume from the motherboard, a critical step to ensure the safety of future work.
Use a plastic shoulder blade or a gloved finger. Pull the connector upwards from the bottom, avoiding pressure on the board itself. Metal tools can damage tracks or cause residual charge to spark.
The old battery in most Xiaomi and Redmi models is glued to the frame on a double-sided tape. Use a suction cup or plastic card to extract it. Raise the edge of the battery and slowly pull, while warming the area under the battery with a hairdryer.
| Xiaomi model | Type of AKB anchorage | Difficulty of extraction | Do you need new glue? |
|---|---|---|---|
| Redmi Note 8/9 | Double-sided scotch | Medium | Yes. |
| Xiaomi Mi 9/10 | Adhesive base + screws | Tall. | Yes. |
| Poco X3 NFC | Strong adhesive layer | Tall. | Yes. |
| Redmi 9A/9C | Removable back cover | Low. | No. |
Clean the seat of old glue residues with an alcohol napkin. The surface should be perfectly smooth and fat-free to securely fix the new element. Stick new adhesive strips complete with the new battery.
Set the new battery tightly pressed over the entire area, plug the plume into the characteristic click, make sure the connector sits smoothly and without skewing, and then you can start the assembly.
Assembly of the device and check of performance
Before the final sealing of the case, you need to do an initial check, turn on the phone without screwing or sticking the lid, check whether charging is determined, whether the battery percentage is displayed correctly, and whether the touchscreen is working.
If all systems are working properly, turn off the device, set the bottom down bar and twist all screws, follow the order of the puffs: first the central, then the angular, to evenly distribute the pressure.
Apply a new adhesive layer (B-7000 or special tape) to the frame of the case. Apply the back cover and press hard around the perimeter. For better adhesion, you can put the phone under the press (for example, under a stack of books) for 1-2 hours.
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The initial start without fixing the cover allows you to avoid redisassembly in the event of a faulty connection of the plume.
After assembly, turn on the phone and let it work for 10-15 minutes. Check the heating in the battery area. Light heat is normal, but the hot spot indicates poor contact or defective element.
Calibration of the new battery
Once a new battery is installed, the power controller may not display the charge level correctly, the system may "think" that the capacity is old, or show percentage surges.