Modern smartphones Xiaomi Mi line famous for excellent performance and capacious batteries, but even the highest quality batteries lose their effectiveness over time. If your phone begins to quickly discharge, turn off in the cold or show the wrong percentage of charge, then most likely it's time to think about replacing the power unit. Self-replacing the battery on Xiaomi Mi is a complex but feasible process that requires accuracy, special tools and understanding of the device gadget. Before starting to disassemble, you need to weigh all the risks, since ineptile actions can lead to damage to the plumes or the display itself.
In this article, we will discuss how to determine the need for replacement, what tools will be required to work and how to safely remove the old battery by installing a new one. It is important to understand that modern smartphones do not have removable batteries in the classical sense, and their body is often sealed or glued together. This is done to protect against moisture and dust, but makes it much more difficult to access internal components. Your task is to act consistently, without applying excessive physical force where patience and heat are required.
There are several signs that indicate that the chemical battery is exhausted, and don't ignore these signals, because a ballooned battery can damage the screen or motherboard, and let's look at the main symptoms of degradation and prepare for the replacement procedure.
Diagnosis of battery condition and signs of wear
The first step before buying a new part is to thoroughly diagnose the current state of the power system. Software methods allow you to get the initial information, but a physical examination often gives a more accurate picture. 20-30% When charged, it is a sure sign that the actual capacity has fallen below the critical level, and it is also worth paying attention to the charging time: if the phone charges suspiciously fast (for example, if the phone is charged suspiciously fast). 30-40 minute 100%), This indicates a loss of capacity.
Special attention should be paid to the appearance of the device. Battery bloating is not just a defect, but a serious security threat. If the back cover has moved, the screen has started to bulge out of the frame, or the phone has stopped lying on a flat surface and rotates when you press the corner, then there has been a gas formation inside, in which case the operation of the device is prohibited until the moment of replacement, since the pressure inside the housing can lead to ignition or explosion.
⚠️ Warning: If you find a battery bloating, do not attempt to puncture or compress it very hard, and this can cause the lithium polymer cell to burn instantly.
You can use built-in MIUI or third-party utilities to program the test, and you can see the current battery health (Health) on the engineering menu or through special applications like Ampere or AccuBattery. However, the most accurate method is the load test and the visual inspection after opening. If the software tests show wear and tear of more than 20-25%, replacing it will be the only way to return comfortable use of the gadget.
Another important aspect is heating. If the case of the smartphone is significantly heated in the camera or center of the back during standby or light tasks (browsing, messengers), this may indicate a high internal resistance of the battery, such heating not only reduces autonomy, but also negatively affects the operation of the processor and other components.
Tools and workplace preparation required
A high-quality battery replacement with Xiaomi Mi is impossible without the right tools. Attempting to open a phone with a knife or credit card often ends with chipped frames or a broken screen. You will need a set of specialized tools that will provide safe access to the insides of the device. The main element is a heating device: it can be a professional heating pad, a temperature-adjusted hair dryer or even a household tile (with caution).
To work with small screws and components, you will need precision screwdrivers. Xiaomi smartphones most often use screws with PH00 (cross) and Y0 or Y00 (tri-sided (“Tri-wing”). The lack of the right screwdriver can lead to the licking of the screw hats, which will make further disassembly almost impossible without drilling, and plastic blades (mediators), a sucker to lift the lid and dielectric tip tweezers.
☑️ Battery replacement tools
Don't forget to prepare the adhesive for reassembly. The original adhesive film (water repellent pad) is ideal, but at home, the most commonly used liquid adhesive is the B-7000 or T-7000. They have sufficient elasticity after drying, which will allow you to reopen the device if necessary. Double-sided tape is not recommended, as it does not hold the lid well when heated and eventually dries.
The workplace should be well lit and organized. Use a magnetic mat or a container with cells to sort screws, as different Xiaomi models (e.g. Mi 9, Mi 10, Mi 11) use screws of different lengths. Installing a long screw in the hole for a short one can lead to breakages on the board or damage to the thread. It is also recommended to have isopropyl alcohol on hand to clean surfaces from old glue.
The process of disassembling the Xiaomi Mi body
The beginning of work is always the same: turn off the smartphone and remove the tray SIM-This is a mandatory action that prevents accidental short circuits and allows you to access the screws if they are located under the tray. Next is the heating step, put the phone back cover up on the heated surface or evenly warm the perimeter with a hairdryer. Temperatures shall not exceed 80-90 degrees Celsius, so as not to damage the oleophobic screen covering or plastic frame elements.
After 3-5 minutes of heating, carefully place the suction cup at the bottom of the back cover and pull up slightly to create a gap. Insert a thin plastic mediator into the resulting gap. Move the blade along the perimeter, cutting the adhesive layer. Be especially careful in the corners and in the area of the camera module, where the adhesive can be applied with a thicker layer. Do not immerse the tool deeper than 3-4 mm, so as not to touch the plumes coming from the side buttons or the main board.
When the lid is separated around the perimeter, don't try to remove it completely. Many Xiaomi models have a fingerprint scanner plume attached to the back cover. A sudden movement will cause this delicately connected component to break. First, find the plume connector (usually in the bottom or top, closer to the center) and disconnect it, pre-unscrewing the metal plate, if any.
What to do if the lid does not open?
When you remove the back cover, you will have access to the internal structure, and in some models (such as the Mi Note series or the glass versions of the Mi 9), there is another protective plate under the cover or the back cover. NFC-And then you have to carefully dismantle them, remembering the location of each screw, and then you have to have the battery available.
Dismantling an old battery and installing a new one
The battery in Xiaomi smartphones is usually glued to a frame or plastic base on bilateral tape. You can not remove it "dry" categorically - there is a high risk of damaging the battery shell, which will lead to its fire, or breaking the display on the back side (since it is glued to the frame). Before extracting, you need to apply a solvent (isopropyl alcohol) under the battery. For this, it is convenient to use a syringe with a thin needle, injecting liquid into the gap between the battery and the case.
Give the alcohol time to act (2-3 minutes), then gently tuck the edge of the battery with a plastic spatula. Use special hoods if they are preserved on the old battery (usually black or green tongues with the inscription "Pull"). Pull them slowly and at a sharp angle to the surface. If the tapes are not, continue to inject alcohol and gently loosen the battery, pushing the shoulder blade deeper. Never use metal tools to tamper with the battery so as not to break through it.
| Xiaomi model | Capacity (mAh) | Type of attachment | Difficulty replacing |
|---|---|---|---|
| Xiaomi Mi 9 | 3300 | Glue + ribbons | Medium |
| Xiaomi Mi 10 | 4780 | Strong glue | Tall. |
| Xiaomi Mi 11 | 4600 | Glue + frame | Tall. |
| Xiaomi Mi 8 | 3400 | Glue + ribbons | Medium |
When the old battery is removed, carefully clean the seat of the residue of old glue and tape. The surface should be perfectly smooth and clean, so that the new battery lay flat and held reliably. Degrease the frame with alcohol. Before installing a new battery, it is recommended to check its voltage with a multimeter - it should be in the range of 3.7-3.8 V. If the voltage is below 3.0 V, the battery can be deeply discharged and require "rocking".
Stick strips of double-sided tape on the new battery (usually complete with spare parts) or apply a thin layer of glue around the perimeter (avoiding the center where there may be bloating). Carefully install the battery in place, combining the connector. Connect the battery plume to the motherboard before clicking. The first onset is better done before the final gluing of the case to make sure that the new part is healthy and the connection is correct.
💡
For better fixation of the new battery in the first 2-3 hours after assembly, use rubber rings or a load (book), pressing the phone in the battery area. This will ensure uniform grip of the glue.
Assembly of the device and check of performance
After a successful test (the smartphone is on, showing charging and percentage of charge), you can proceed to the final assembly. If you used liquid glue, apply a thin continuous line along the perimeter of the frame (or along the old glue track). Be careful: the glue should not get to the camera, speaker or connectors. Carefully combine the back cover with the body and evenly press the entire perimeter. Make sure that there are no gaps and clicks when pressed.
Wrap all the screws in reverse sequence. Remember that the screws around the camera module or charging connector can vary in length. Write them without undue effort to avoid breaking the thread in the plastic bushings. Put decorative plugs and trays in place. SIM-Wipe the case from fingerprints and glue marks.
After assembly, you need to calibrate the battery. To do this, discharge the phone until completely turned off (0%), then charge and charge to 100% when turned off. After reaching 100%, hold on charging for another 1-2 hours. Then turn on the phone. This procedure will help the power controller (BMS) correctly determine the real capacity of the new element and correctly display the percentages.
⚠️ Warning: If the battery is not switched on after the battery is replaced or if the phone shows a connection error, don't panic. Check the density of the battery connector. Sometimes it takes a few seconds for the system to recognize the new power module. If the problem persists, the new battery itself or the plume may be faulty.
Frequent errors and precautions
Self-repair is always a risk. One of the most common mistakes is overheating the device. Prolonged exposure to high temperatures can lead to detachment of the display (the appearance of yellow spots) or damage to the adhesive layer of the oleophobic coating. Use a thermometer or rely on tactile sensations: the body should be hot, but not burning.
Another common problem is damage to the plumes. The main camera plume, charging plume and side button plume often pass very close to the edges of the case. Careless movement of the shoulder blade can tear them. If you feel resistance, stop and inspect the gap in good light. It is also dangerous to damage the battery itself with a tool - even a small puncture can cause a chemical reaction with the release of caustic smoke.
- 🔥 Overheating: Don’t keep the hair dryer on too long at one point, move it evenly.
- 🔧 Tools: Do not use metal blades to separate the cover, only plastic.
- 🔋 Safety: Avoid contact with the battery electrolyte if it is damaged (rinse with water and soap).
- 🧹 Cleanliness: Dust and villi under the glue will lead to poor tightness and gaps.
Low-quality battery replicas are another risk: Cheap ones can have real capacity 2-3 times smaller than the declared capacity, quickly degrade or lack adequate protection against overload. Buy components only from trusted suppliers, paying attention to the presence of holograms and the quality of printing on the battery case.
💡
The secret to success is patience: 90% of battery replacement failures are due to rush and a desire to finish the process faster, ignoring heat and accuracy.