The Xiaomi Mi A2, launched as part of the Android One program, has proven to be a reliable device with a clean interface and decent performance. However, time spares no one, and lithium-polymer batteries tend to degrade. If your phone starts to quickly discharge, turn off at 15-20% charge or swell, replacing the battery becomes the only sure solution to extend the life of the gadget.
The replacement procedure in this model has its own nuances, since the body is made without a removable cover, and the interior space is optimized for maximum compactness. You will need not only a new battery, but also a specific set of tools, as well as patience. Incorrect disassembly can lead to damage to the plumes or break the rear window, so it is important to follow the sequence of actions.
In this guide, we will take a closer look at the process of dismantling an old battery and installing a new one, focusing on safety and calibration of the power system. You will learn how to distinguish a quality component from a fake, which tools are mandatory to use and how to avoid common assembly errors. Properly executed procedure will return the smartphone to autonomy comparable to factory performance.
Diagnostics and selection of a new battery
Before you start physically disassembling the device, you need to make sure that the problem lies in the physical wear of the battery. Sometimes software failures or background processes create the illusion of a quick discharge. Check the battery usage statistics in the Settings → Battery menu. If the discharge schedule is uneven or the phone turns off when there is a charge, this is a sure sign of the need to replace.
When choosing a new battery for the Xiaomi Mi A2, it is critical to pay attention to the capacity and manufacturer.The original capacity is 3010 mAh. Attempting to install a battery with an overestimated performance (for example, 4000 mAh) in a housing of the same thickness is physically impossible without changing the chemical composition, which often leads to a decrease in real efficiency and fire hazard.
There are many copies in the parts market that may not have the proper quality control board (BMS), which is responsible for controlling overcharging, overheating and short circuits, and using cheap analogues can cause the power controller on the motherboard to fail, making repairs economically inefficient.
Note the marking and appearance of the plume. In original or quality compatible batteries, the plume is flexible, with a clear print and a reliable connector. Cheap copies often have a rigid plume that can crack when installed, or a connector that does not provide tight contact.
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When buying a battery, pay attention to the date of production. Lithium batteries degrade even during storage, so do not take the element that has been in storage for more than 1-2 years.
You can also use special applications to read data from the battery controller, but a physical examination after opening will give the most accurate picture. Bloating is an unambiguous signal to be replaced immediately, since the pressure inside the housing can damage the display or rear window.
Tools and workplace preparation required
Quality repairs start with the right organization of workspace. To replace the battery in the Xiaomi Mi A2, you will need a specialized set of tools, since the device does not involve simply removing the lid. Lack of preparation can lead to damage to the fasteners or injuries.
The main list of tools includes:
- 🔥 A hair dryer or thermophene to soften the glue (temperature near 80-90°C).
- 🔧 Set of screwdrivers (cross-haired) PH000 flat).
- 💳 Plastic cards or mediators for opening the body.
- 🧲 Magnetic mat or organizer for screws.
- 🧴 Isopropyl alcohol and sucker.
Special attention should be paid to the source of heating. The use of open fires or household irons is unacceptable, as they create uneven heating. Thermophen allows you to point the adhesive layer around the perimeter of the rear panel without overheating the internal components, such as the camera or display.
Before starting work, be sure to turn off your smartphone. If the battery is swollen and prevents the device from turning off, or if the phone turns off itself, try to minimize the time between heating and disconnecting the battery plume from the board to avoid short circuit. The workplace should be well lit and have no conductive surfaces.
☑️ Preparation for repairs
The process of dismantling the back panel and components
The back cover of the Xiaomi Mi A2 is glued around the perimeter. To remove it, you need to warm up the edges of the body evenly with a hairdryer for 1-2 minutes. Don't hold the hairdryer too close so as not to damage the paint or glass. After heating, insert the suction cup at the bottom of the back panel and gently pull, creating a gap.
Insert a plastic mediator or a thin plastic card into the gap, drive the instrument along the perimeter, gradually cutting the adhesive layer, move slowly, avoiding sudden jerks, as there are plumes under the glass that can be damaged if you move carelessly.
Once you remove the back cover, you'll have access to the insides of the smartphone, and the first thing you need to do is unscrew the screws that lock the protective plate that covers the plumes of the display and the battery, and they're usually around. 10-12 They can be of different lengths, so it is important to remember or fix the location of each screw.
⚠️ Warning: The metal plate may have hidden screws under the stickers or be glued.Do not use force if the plate is not removed - check for additional fasteners.
When you remove the plate, the first thing you do is disconnect the battery connector from the motherboard, which is a critical safety step, and only after you de-energize the device, you can disconnect the plumes of the display and other modules, and then you can use a plastic blade to turn off, pressing the connector itself, not the plume.
Why is it important to turn off the battery first?
Removing the old battery and installing a new one
The battery in the Xiaomi Mi A2 is fixed to double-sided tape, which loses its properties over time, but becomes very sticky when heated. Removal will require heating again. Put the smartphone down with the screen (pre-protecting it) and warm up the rear in the battery area.
The use of metal tools to tamper with the battery is strictly prohibited. A puncture of a lithium polymer cell will cause instant chemical reaction, ignition and eventual explosion. Use only plastic cards, gently putting the battery on different sides.
If the new battery comes with a sticky base, remove the residue of the old glue from the smartphone body. Degrease the surface with alcohol. Set the new battery tightly pressed to hold it tightly. Connect the connector to a characteristic click, making sure it sat flat and without skewing.
Before the final assembly, it makes sense to do a pre-inspection, plug the display plume in and try to turn the device on without sticking the back cover, and if the phone is on, shows the correct percentage of charge, and responds to the charger connection, the replacement has been successful.
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The main risk of retrieval is damage to the battery shell, and any puncture or deep scratch makes the battery unusable and dangerous.
Comparison of characteristics: Original vs Analogues
The choice between the original and the analogue parts often comes before the owner, and here is a table that helps you understand the key differences and risks associated with using different types of batteries for the Xiaomi Mi A2.
| Characteristics | Original (OEM) | High quality analogue (High Copy) | Cheap copy |
|---|---|---|---|
| Capacity | Strictly 3,010 mAh | 2800-3000 mAh | Claimed more, really 1500-2000 mAh |
| Cycle resource | 500+ cycles | 300-400 cycles | 50-100 cycles |
| Protection (BMS) | Complete set | Basic level | Absent or incorrect |
| Price. | Tall. | Medium | Low. |
As you can see from the table, savings on cheap copies often go sideways. Low cycle life means that after 2-3 months you will have to disassemble the phone again. In addition, incorrect operation of the controller in cheap analogues can lead to improper display of the percentage of charge.
High-quality third-party brands (e.g. Nohon, Cameron Sino) are often a reasonable alternative if the original is not available. They provide honest capacity and have the necessary protections. However, even they can be inferior to the original in calibration accuracy of the sensors.
Device assembly and battery calibration
Once you've done a successful test, you can start the final assembly, put the metal plate in place, twist all the screws in the right order, and don't drag the screws, especially those next to the plastic, so you don't rip the thread.
Apply new glue or special adhesive tapes (B-7000 or analogues) around the perimeter of the case. Press the back cover and lock it with rubber bands for 15-20 minutes until the glue is completely dry. Make sure that the gaps between the screen and the frame are uniform.
After assembly, it is recommended to perform a calibration procedure. Completely discharge the smartphone before turning off. Then put it on charge when turned off to 100%. After reaching 100%, hold on charging for another 1-2 hours. Then turn on the phone and, if it does not show 100%, finish the charge. This will help the power system correctly determine the real capacity of the new element.
In the first days of use, watch the heating of the device. Light heating in the battery area on the first charge is acceptable (chemical activation is taking place), but strong heating indicates problems with the contact or quality of the battery itself.