Decreasing autonomy is an inevitable stage in the life of any modern gadget, and owners of popular Xiaomi devices are no exception. When the phone stops living until the evening or suddenly turns off at 20-30% charge, the question arises about the need for technical intervention. Replacing the battery in a Xiaomi smartphone is a procedure that many decide to perform on their own, wanting to save on the services of a service center and be sure of the quality of the installed part. However, this process requires not only the presence of a new battery, but also some technical training, accuracy and understanding of the risks associated with disassembling sealed housings.
In current models, whether it’s the budget Redmi Note or the flagship Mi, manufacturers use adhesives to lock the battery, which makes it much more difficult to dismantle compared to devices from a decade ago. It’s important to understand that self-replacement is not warranty if it’s still valid, so weigh the pros and cons before you start. In this article, we’ll take a closer look at the entire process, from choosing a quality battery to final assembly, to minimize the risks of damage to the plumes or screen.
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 chemical element, and not in software failures or incorrect calibration. If your Xiaomi smartphone discharges quickly, warms up in plain or inflated, then a replacement is inevitable. It is critical to choose the right battery model, as the market is oversaturated with cheap copies that can not only quickly fail, but also damage the motherboard's power controller, QR-authentication codes and appropriate container marking.
When choosing a cell, you should pay attention to the manufacturer of the cell: it is preferable to take originals or certified analogues from well-known brands like Nohon or Deji. Cheap “nonaime” options often have a real capacity of half the declared one, which will lead to a re-disassembly of the phone in a couple of months.
- 🔋 Check the phone model in About Phone settings for an accurate search for a compatible battery.
- 🔋 Look for the marking of the recharge cycle: a quality battery withstands 500-800 full-cycle.
- 🔋 Pay attention to the availability of protective fees (BMS) At the end of the battery, it prevents overheating.
- 🔋 Make sure that the plume connector matches the original, as the physical location of the contacts may differ.
⚠️ Warning: Never buy batteries without packaging and protective film on contacts – this is a sign of a violation of storage conditions or poor quality.
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Buy batteries with a production date indicator – lithium-ion cells degrade even during storage, so the battery, which has been in storage for 3 years, has already lost some of the capacity.
Tools and workplace preparation required
Qualitative battery replacement in Xiaomi is impossible without a specialized set of tools. Using inappropriate items such as knives or pins significantly increases the risk of damage to internal components, especially thin plumes of the display and connectors. The standard set of masters includes a suction cup to open the case, a set of screwdrivers (most often cross PH00 and PH000), plastic mediators (scapula) and tweezers with curved edges. To work with adhe layers will require a heating source, which can be used professional thermofen, or with great care.
The organization of the workspace is the key to success. You need a clean, well-lit surface, preferably with an antistatic mat or just a clean sheet of paper. All screws when disassembled are better laid out in order of their extraction or use a magnetic mat with markings, because different Xiaomi models use screws of different lengths, and if you mix them up during assembly, you can damage the thread or break through the body.
☑️ Ready for repair
The process of disassembling the smartphone body
Modern Xiaomi smartphones, especially the Redmi Note series and the flagship Mi, have glass or plastic back covers glued around the perimeter. The first step should always be to turn off the device. Then you need to carefully warm the perimeter of the rear cover. The heating temperature should not exceed 80-90 degrees Celsius, so as not to damage the display matrix on the back side or melt the plastic elements of the internal structure.
After warming up, insert a suction cup at the bottom of the lid, pull it back, creating a small gap, and gently enter a thin plastic mediator. Drive the tool along the edges, cutting the glue. Don't try to slash the lid sharply - the glass can crack. In some models, such as the Redmi Note 9 Pro or Xiaomi Mi 9T, under the lid immediately opens access to the screws of the camera module and speaker, which also need to be unscrewed before removing the protective plastic panel covering the "stuffing" of the smartphone.
Removing the protective plate requires special care, since the plumes of the display and touch screen often pass under it. You need to disconnect the plumes from the motherboard only after removing the protective metal or plastic plate covering the connectors.
⚠️ Warning: If the cover doesn’t lend itself and the glue doesn’t soften, add a little more heat, but don’t use force to break the rear window, which in many Xiaomi models is part of the design and only changes when assembled.
Removing the old and installing a new battery
The hardest part of replacing a battery in Xiaomi is removing it. Manufacturers use double-sided tape or a special glue to fix the battery to prevent it from shifting and improve heat sink. You can't just pull it out with your fingers. There are often plumes under the battery, so it's strictly forbidden to squeal it with metal tools on the bottom, you're guaranteed to damage the plume of the display or touchscreen, which will lead to stripes on the screen or loss of touch control.
Use a thin line, floss or special plastic cards to extract safely. Strip the thread under the battery and side-to-side sawing movements. Gradually cut the glue layer. If your model has special retractable tongues (often found in Xiaomi), carefully pull them. Before installing a new battery, you must carefully clean the landing place of old glue and tape, degreasing the surface with alcohol. On the new battery, you should paste fresh strips of bilateral tape (usually come with a complete set), ensuring reliable fixation.
Installing a new battery requires a precise alignment of the connector. First, gently insert the connector into the back of the board, making sure it sat down before the characteristic click, and only then put the battery body in a niche. Do not press the battery hard immediately until you make sure that the plume is not squeezed and lies flat. After connecting, it is recommended to immediately check the device's performance without sticking the lid permanently.
What to do if the battery is swelling?
Comparison of battery types in Xiaomi devices
Understanding the differences between battery types helps you better navigate the characteristics and expectations of autonomy. Xiaomi smartphones use lithium-polymer (Li-Po) and lithium-ion (Li-Ion) batteries, and although the chemical processes are similar, design differences affect shape, weight and safety.
| Characteristics | Li-Ion (Lithium-ion) | Li-Po (Lithium-polymer) |
|---|---|---|
| Form | Standard, more often cylindrical or rectangular in a rigid body | Any flexible, soft polymer shell |
| Weight. | It's heavier with the same capacity. | Easy, 20-30%. |
| Security | Risk of explosion for damage is higher | Less prone to ignition |
| The memory effect | Virtually absent | Absent completely. |
| Applications in Xiaomi | Budget and old models | Modern smartphones (Mi, Redmi, POCO) |
Most modern models, such as the Xiaomi Redmi Note 12 or POCO X5, are equipped with Li-Po batteries. They allow you to create ultra-thin devices and place the battery in a non-standard shape, taking up maximum free space inside the case to increase capacity. Which is why it is important to buy a battery specific to your model, not a universal one, since the dimensions can vary by millimeters, which will lead to the inability to close the lid.
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Always choose the same battery type (Li-Po) as the manufacturer has installed to ensure that the charge controller is working properly.
Assembly and primary calibration
After successfully installing the battery and checking the smartphone on (the screen caught fire, loading appeared), you can proceed to the final assembly. Wipe the inner surface of the back cover and the smartphone frame from dust and fingerprints. Apply a new adhesive compound (B-7000 or special glue-scotch) along the perimeter of the frame with a thin strip. Avoid getting glue on the camera, speaker and charging connector. Press the cover tightly and lock the device with rubber rings or cargo for 1-2 hours until completely dry.
After assembly, you need to calibrate the battery, which is a process that helps the power controller correctly display the percentage of charge. To do this, discharge the phone until it is completely turned off (0%), then charge it when it is turned off to 100%. After reaching full charge, hold on to charging for another hour. Then turn on the phone. If the indicator is less than 100%, recharge to the end. Repeat the procedure 2-3 times. This will help the MIUI system correctly recalculate the capacity of the new battery.
In the first days of use, watch the heating temperature. The new battery may warm a little while the chemical layer is formed, but the strong heating indicates problems with the controller or short circuit. It is also worth watching the discharge rate: if it is comparable to the new device, then the replacement was successful.
- 📱 Let the glue dry for at least 2 hours before active use of the phone.
- 📱 Do not use your phone during the first charge after replacement to avoid power surges.
- 📱 Check the operation of all buttons and vibrator before the final fixation of the cover.
⚠️ Note: If after replacement the phone is cyclically restarted or shows an incorrect percentage of charge, it is possible that the battery connector is not fully connected or the contacts on the board have oxidized.