Redmi series smartphones are deservedly popular due to their excellent value for money, but even the most reliable lithium-polymer batteries lose their capacity over time. If your phone starts to run out in a couple of hours, turns off at 20% charge or the case is swollen, then it's time to think about replacing the battery, a common problem that gadget owners face after 2-3 years of active use.
Many users are afraid to open the device on their own, fearing damage to the plumes or break the tightness, but with minimal skills and the right tools, the procedure is quite feasible at home. In this article, we will discuss in detail the process of dismantling the old and installing a new battery, paying special attention to the nuances of working with adhesive connections and plumes of different Xiaomi models.
Before you start any work, you need to make sure that you accurately diagnose the problem with the power source, not the charge controller or software. Often a software calibration failure can mimic the symptoms of a worn battery, so it is worth trying to reset or refashion the device before buying new components. If the software methods did not help and the phone is unstable only with the current battery, then a physical replacement is the only right solution.
Diagnosis and selection of components
Before ordering a new battery, it is critical to conduct a thorough diagnosis of the current state of the smartphone to exclude software errors and accurately identify the battery model. Xiaomi owners have a unique advantage - a built-in engineering menu that allows you to get comprehensive information about the status of the BMS (Battery Management System) without installing third-party applications. To access this data, you need to open the Phone application and enter a special code # # # # #6485#, after which a table with technical parameters will appear on the screen.
In the menu that opens, you should be interested in several key indicators that will help you understand the degree of degradation of the chemical composition of the elements. MB_06 The battery is in the general state (good or bad) and MB_00 It shows the current percentage of charge, which may be different from what the system shows. MF_02 (Cycle Count, which indicates the number of complete recharge cycles: if the value exceeds 500-600 Loss of capacity is a natural physical process, not a marriage.
⚠️ Attention: If the parameter MF_05 (Actual Capacity: Values are significantly lower 80% nominal-capacity (MF_06), This is a direct signal to replace. MF_07 — if it shows the voltage below 3.6In the charged state, the chemical structure of the cell is irreversibly destroyed.
When choosing a new battery for Xiaomi Redmi, it is extremely important to avoid cheap analogues of unknown manufacturers, which often have a real capacity of half the declared. MI or BMI and have a hologram with QR-The market is saturated with fakes, so when buying, pay attention to the quality of printing, the clarity of fonts and the presence of protective stickers on the contacts.
Tools and workplace preparation required
A high-quality battery replacement is impossible without a specialized set of tools, since modern Xiaomi smartphones are assembled using a large amount of glue and have a dense layout of internal components. The basic gentleman's set of masters should include a set of precision screwdrivers (cross PH000, PH00 and flat), plastic mediators (scapula) to open the case and a metal thin scalpel to work with adhesive layers. The use of metal tools inside the case is allowed only by experienced craftsmen, beginners it is better to limit themselves to plastic to avoid short circuits.
To soften the glue that holds the back cover or display module, you will need a heat source, which is most often used as a construction hair dryer or a special heater (separator). A normal household hair dryer may not cope with the task, as it takes too much time to warm up, which can lead to overheating of the internal components, so it is better to use professional equipment with temperature control.
☑️ Checklist for repair preparations
The organization of the workspace is no less important than the availability of tools, since the loss of even one microscopic screw can turn a simple repair into an insoluble problem. It is recommended to use a magnetic mat or a sheet of paper marked on squares, where you will lay the screws in order of their twisting with a brief description of the location. Before starting work, be sure to turn off the smartphone completely to eliminate the risk of short circuit of the conductive paths of the motherboard during careless movement.
The process of disassembling the Redmi smartphone
The procedure for disassembling Redmi smartphones can vary significantly depending on the specific model and year of release, as the company's engineers use different design solutions to attach elements. 4, 5, Note 4-7) The back cover is often a removable plastic element that is held on the latches around the perimeter and requires minimal intervention to remove. In such cases, it is enough to gently apply the cover with a mediator in a specially provided recess or through the connector. micro-USB/USB-C and hold the instrument along the entire circuit.
Modern models, starting with the Redmi Note 8 and later, have moved to the “sandwich” design, where the back cover (glass or plastic) is glued around the perimeter with a powerful adhesive composition. To dismantle such a cover, you need to evenly warm the perimeter of the device to a temperature of 80-90 degrees Celsius for 2-3 minutes, constantly monitoring the temperature so as not to damage the display matrix or internal plastic frames. After warming up, insert a suction cup in the lower part of the case, create a vacuum, slightly pull up and simultaneously inject a thin media slitor into the slit.
⚠️ Warning: When working with glass back covers, be extremely careful – they are very fragile and can crack from uneven pressure or local overheating. Move the blade or mediator only parallel to the plane of the body, without going inside, so as not to cut the plumes coming from the buttons or fingerprint scanner.
When you successfully remove the back panel, you will see the inside of the smartphone, where you can access the battery with a plastic or metal decorative bar, which is usually fixed by several screws of different sizes that need to be twisted and sorted, remembering their location, because a longer screw screw screw screwed into a short hole can penetrate the motherboard. In some Redmi models, an antenna connector or a main camera plume can also be located under this bar, which requires additional care when dismantling.
Removing the old battery and installing a new one
The most important step is to disconnect the battery plume from the motherboard, since careless movement can lead to a failure of the power controller or short circuit. Before touching the connector, you need to visually assess its condition: if you see traces of oxidation or moisture, cleaning should be done extremely carefully, using a soft brush and minimal alcohol.
In most modern smartphones Xiaomi battery is fixed on double-sided tape or adhesive stripes located under the power element, which greatly complicates its extraction. It is strictly forbidden to try to tamper the battery with metal objects or apply force to the center of the cell, as damage to the shell of the lithium polymer battery can lead to its fire or explosion. For safe extraction, use special hood strips (if they are provided by the design) or carefully poke the battery with a plastic card from the edges, preheating the rear wall of the case.
Installing the new battery requires pre-positioning: the remnants of the old glue must be carefully removed, degrease the surface and apply a fresh layer of special glue B-7000 or T-7000. The glue is applied in a thin strip along the perimeter of the pad, avoiding hitting the camera, plumes and speaker, after which the new battery is carefully installed in place and slightly pressed to fix. It is important to make sure that the battery connector exactly matches the response part on the board before snapping it to the characteristic click.
Device assembly and initial calibration
The assembly of the smartphone is done in the order, reverse disassembly, but this process also has its technical nuances, ignoring which can lead to the appearance of backlashes or problems with the sensor. Before installing the back cover, be sure to check whether all the screws are returned to their places, since the absence of even one fastener can lead to extraneous sounds (rattle) when the vibrator or speaker. Decorative slats should be installed carefully, making sure that their edges do not clamp the plumes, which is especially important for models with subscreen scanners.
Once the device is physically assembled and turned on, you don't expect the charge indicator to work instantly, because the power controller doesn't yet "understand" that it has a new power source. To properly operate the power system, you need to calibrate the device to full discharge before automatically turning off, followed by charging to 100% when it's off, a process that helps MIUI or HyperOS software re-determine the real capacity and correctly display the percentage of charge.
In some cases, after a battery change, it may be necessary to reset to factory settings or flash if the system continues to show errors or discharges quickly. This is due to the fact that the controller may have left error logs from the old battery that prevent the new battery from working correctly. If after two full charge-discharge cycles the problem persists, it makes sense to check the voltage at the battery contacts with a multimeter or consult a specialist to diagnose the charge chain.
Comparison of battery characteristics
Understanding the differences between original batteries and high-end counterparts will help you make an informed decision when buying, as the price gap can be significant. Below is a table comparing key parameters that affect the durability and safety of using a smartphone after repair.
| Parameter | Original (OEM) | Quality analogue | Cheap copy |
|---|---|---|---|
| Real capacity | 100% (claimed) | 90-95% | 60-70% |
| Number of cycles | 500-800 | 300-500 | 100-200 |
| BMS protection | Complete. | Basic | Absent. |
| Rate of degradation | Low. | Medium | Tall. |
The choice in favor of original components is always justified if you plan to use a smartphone for several more years, since the voltage stability and protection against overheating in the originals are implemented at the highest level. Analogues can be an acceptable option for budget models or phones that are planned to be sold in the near future, but the risk of bloating after six months of operation in them is much higher. Cheap copies are strongly not recommended for installation, since the lack of protection can lead to damage to the motherboard.