Modern smartphones, including popular models from Xiaomi, Redmi and Poco, inevitably lose their autonomy over time. If your device stops holding charge, turns off 20-30% or swells, then it’s time to change the power source. This is one of the most common reasons for going to service centers, but with the minimum skills and the right tools, you can do it yourself at home.
It is important to understand that opening the case of a smartphone is always a risk that can lead to loss of warranty or damage to other components. However, if you are careful and attentive to detail, replacing the battery will take a short time and save a significant amount. In this article, we will discuss in detail the process of dismantling, selecting a new part and installing the right one.
Before you start disassembling, you need to make sure that the problem is the wear of the battery, not the software failure or malfunction of the charge controller. Normal wear is the loss of 20% of capacity after 500 full charging cycles. If your phone is already 2-3 years old, the degradation of the chemical composition of the battery is a natural process that requires intervention.
Diagnosis of battery status and preparation
The first step is to make an accurate diagnosis of the current state of the food system. MIUI And HyperOS doesn't have a built-in, detailed battery health report like iOS, so you'll have to use third-party tools or an engineering menu ##6485##. In the menu that opens, find the parameter. MB_06 (battery status; and MF_05 (full-cycle).
If the status is bad or the number of cycles is more than 500, you need to replace it. Also, pay attention to the physical condition of the case: if the back cover starts to move away or the screen slightly rises, this is a sure sign of bloating, in which case you need to act extremely carefully so as not to damage the display or plumes.
To do this successfully, you'll need to prepare your workplace, which should be well lit and the desk free of unnecessary objects. 20-25%, because working with a fully charged lithium polymer battery increases the risk of fire in case of accidental damage.
- 🛠️ Screwdriver kit: cross (PH000) for screw board and asterisk (Torx) T4/T5) screw-hole.
- 🔥 Hair dryer or heating plate: necessary to soften the glue fixing the back cover.
- 💳 Plastic cards or mediators: for neat opening of the body without scratches.
- 🧴 Clay. B-7000 or double-sided tape: for sealed assembly of the device after replacement.
⚠️ Warning: Never use metal tools (knives, blades) to lick the lid.One awkward movement can damage the plume scanner or tear the display plume, leading to costly repairs.
Choosing the right battery to replace
The mobile component market is crowded with offers, but the quality varies significantly.For Xiaomi smartphones, it is critical to use original batteries or quality analogues from proven brands such as Nohon or BS. Cheap copies often have real capacity 2-3 times less than claimed and can be dangerous.
Original batteries can be recognized by the hologram on the package, QR-The product itself is usually marked with the serial number and production date, and if you order a part online, carefully study the reviews of the seller and ask for a photo of the real product.
The new battery must be as specific as your model, and a larger battery ("reinforced") is possible, but only if its physical dimensions are identical to those of the standard battery, and the thickened element can compress the display or prevent the lid from closing, which will break the tightness of the housing.
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When buying a battery, pay attention to voltage: the standard for Li-Pol is 3.85V or 3.87V. Using a cell with a different voltage can burn the power controller.
The process of heating and opening the case
Modern Xiaomi smartphones are assembled using a large amount of glue to ensure structural rigidity and protection from dust. To open the case without damage, it must be heated. Use a building hair dryer, setting a temperature of about 80-100 degrees, or put the phone down on the heating platform for 3-5 minutes.
You need to check for autopsy carefully by trying to bend the edge of the lid with a mediator. If plastic or glass is easy, you're on the right track. If you feel strong resistance, you need to continue heating. Move around the perimeter, inserting a plastic card into the gap between the frame and the lid.
Be especially careful in the area of the main camera module and the fingerprint scanner, if it is embedded in the button or under the screen. The plumes in these places can pass close to the edges. Do not try to sharply break the lid, act in translational movements, gradually cutting through the adhesive layer.
What to do if the lid cracks at the opening?
Dismantling an old battery and installing a new one
When you take the back cover off, you'll see the inside of the smartphone, and the first thing you need to do is to disconnect the battery plume from the motherboard, and normally the connector is covered with a metal or plastic bar that's locked by the screws, and you need to carefully unscrew them and remove the protection.
The battery itself in most Xiaomi models is glued to the inside of the case or frame. Use special exhaust belts (if designed) to remove it or gently poke the edge of the battery with a plastic blade. It is strictly forbidden to pierce the battery or bend it, this can cause ignition.
Install the new power supply by pre-applied a thin layer of B-7000 glue on the frame or using double-sided tape. Make sure the connector matches perfectly, and snap the connector until a characteristic click. Before final assembly, it is advisable to check the health by briefly turning on the device.
| Xiaomi model | Type of lid attachment | Location of the plume | Difficulty replacing |
|---|---|---|---|
| Redmi Note 9/10 | Glue + screws | Sideways, accessible | Low. |
| Xiaomi Mi 9T / K20 | Clay (mechanism) | Under metal protection | Medium |
| Poco X3 NFC | Screws + glue | Central | Medium |
| Xiaomi 11/12/13 | Strong glue | A complex defense | Tall. |
☑️ Checklist before assembly
Calibration and post-replacement verification
Once the new battery is installed, the system may not display the charge level correctly, as the memory controller will still "remember" the parameters of the old element. To calibrate, fully charge the phone to 100% when it is turned off, then turn it on and use it until completely discharged and turned off. Repeat this cycle 1-2 times.
In some cases, you need to reset battery statistics through an engineering menu or special applications, although in modern versions of Android this happens automatically in the background.
Check all the functions that might have been affected by the disassembly: vibrator, speakers, cameras and scanners. If the phone doesn't turn on after assembly, double-check the density of the battery connector. Often the problem lies in poor contact.
⚠️ Warning: If the phone shows a charge after the change but doesn't turn on, don't try to charge it for a long time.This may indicate a short circuit in the power supply or a malfunction of the new battery.
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Qualitative battery calibration takes up to 3 full charge-discharge cycles, after which the percentage of charge must be displayed correctly.
Typical errors and security measures
The most common mistake is to use aggressive solvents to remove old glue, the liquid can leak under the display or onto the board, causing corrosion of the contacts, and only use isopropyl alcohol and soft tissue to clean the glue residue.
Another mistake is to build a live thread without checking, and if you don't fix the connector's protection screws, vibrations when you ring or fall can cause the contact to go off and suddenly shut down your smartphone. Always lock all the screws in their places.
Before starting work, it is advisable to remove synthetic clothing and touch a grounded metal object to discharge static potential, which can theoretically damage sensitive electronics.
- 🚫 Do not heat your phone above 100 degrees Celsius, it can damage OLED-screen.
- 🔋 Do not keep the extracted battery in your pocket with keys or coins – closing contacts will cause a fire.
- 🧤 Use antistatic gloves or at least dry clean hands to avoid leaving greasy marks on the internal components.