Replace the battery on Xiaomi Redmi 4X with your own hands

Xiaomi Redmi 4X is deservedly considered one of the most reliable devices of the budget segment of its time, but even the highest quality lithium-polymer battery loses capacity over time. If your phone starts to quickly discharge, turn off in the cold or show the wrong percentage of charge, most likely, it's time to replace the energy element. Self-replacement of the battery is a real way to extend the life of the gadget without overpaying for the services of the service center, where often they charge not only for parts, but also for work.

The recovery process requires precision and understanding of modern smartphones, as the Redmi 4X is made of metal and the interior is densely filled with components. Wrong actions can damage the plumes, screen or even bloat the new battery, so it is important to strictly follow the sequence of operations and use the appropriate tools. In this article, we will discuss each step in detail, from preparing the workplace to the initial activation of a new power source.

Owners often experience a device that stops holding charge after 2-3 years of active use, a natural physical process of degradation of chemical compounds inside the cell, and restoring the device to work with their own hands will save a significant amount of money and return the phone to the previous autonomy that it demonstrated in the first months of use.

Diagnostics and selection of a new battery

Before starting disassembly, you need to make sure that the problem lies in the wear of the battery, and not in software failures or a malfunction of the charge controller. Bloating, sharp jumps in percentage of charge (for example, from 40% to 5% per minute) and heating the lower part of the case are direct indicators of the need to replace. If the phone is just slowly charging, it may be a cable or charger, and replacing an expensive component is not necessary.

When choosing a new battery for Redmi 4X It is critical to pay attention to the labeling and capacity of the original, which is 4100 mAh. The market is oversaturated with cheap copies with overrated characteristics that can fail in a few months or damage the motherboard with voltage surges. It is recommended to look for batteries with a protective board BMS (Battery Management System, which prevents overcharging and deep discharge.

Note the connection connector: the model BN41 (standard for Redmi 4X) has a specific shape and location of contacts. Buying a battery with an inappropriate connector will require re-sweetening of wires, which is strongly recommended without professional equipment and skills soldering chips.

• 🔋 Capacity: look for honest 4000-4100 mAch, avoiding the inscriptions 5000+ mAch on cheap brands.
• 🔌 Connector: Must match exactly with the original connector on the board without the need for soldering.
• 🛡️ Protection: the presence of a built-in board for protection against overheating and short circuit is mandatory.
• 🏷️ Marking: model BN41 It is the standard for this series of Xiaomi smartphones.

⚠️ Warning: Never buy batteries without protective film on contacts or with a damaged case - the risk of fire of such a element is extremely high.

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When buying, pay attention to the battery's production date. Lithium batteries age even on the shelf, so a cell that has lain for more than 2 years may have reduced capacity.

Tools and workplace preparation required

Quality repair is impossible without the right tools, as the design of Xiaomi Redmi 4X involves the use of screws of different sizes and brittle plumes. You will need a set of precision screwdrivers, including cross (PH000, PH00) and possibly triangular (Tri-wing) for some modifications, although this model is more often used standard screws, and plastic blades (mediators) to open the case without damaging metal and paint.

Special attention should be paid to the organization of the workspace: the table should be well lit, and all small screws should be sorted immediately by the stages of disassembly, so as not to confuse them during assembly. Using a magnetic mat or ordinary white paper, which shows all the details, will help to avoid the loss of microscopic fasteners that can easily roll under the furniture.

Safely removing the old battery, which is often glued to double-sided tape, will require a dryer to heat the glue and a thin line or a special card.Do not use metal objects to tamper with the battery, as a puncture of the lithium-polymer cell shell causes instant ignition and toxic smoke.

The process of disassembling the body and removing the rear panel

The first step is to carefully remove the metal back cover, which is held on an adhesive basis around the perimeter. To do this, you need to warm the perimeter of the body with a hairdryer to a temperature of about 60-70 degrees Celsius for 2-3 minutes, constantly checking the heating with your finger so as not to overheat the screen matrix on the front side. After even warming up, insert the suction cup into the bottom of the cover (near the logo or below) and slightly pull up, creating a gap.

Insert a plastic mediator into the gap, and as you slid along the edges, snap the clips and cut through the glue. Move slowly, without putting too much effort, as the metal of the lid can deform, and poor-quality paint can get off. Be especially careful in the upper part where the speakers and the camera holes are located.

Once the lid is successfully detached, you'll see the internal layout closed by a plastic frame that also attaches to the screws. At this point, it's important not to pull any plumes unless they're disconnected, and to carefully inspect the integrity of the visible components. Any damage to the display plume or camera module if you open them neatly can lead to costly repairs.

Disconnecting plumes and removing the old battery

Once the decorative plastic pad is removed, the main board and battery are accessed, and the first step is to disconnect the battery plume from the motherboard to shut the device down and avoid short circuits in further manipulations, and use a plastic blade or nail, putting the connector vertically upwards, avoiding lateral loads on the connector.

Next, unscrew all the screws that fix the plastic frame of the speaker and protective plates over the connectors of the plumes. In Redmi 4X, the battery occupies most of the internal volume and is glued to the frame on a powerful double-sided tape. To extract it, reheat the battery area with a hairdryer (already through open space) and use a plastic card for tweaking.

It is strictly forbidden to use metal tools to tamper with the battery, since even a microscopic puncture causes a violent chemical reaction with the release of heat and fire. If the battery sits very tightly, you can use medical alcohol or a special liquid to dissolve the glue by dripping a couple of drops around the perimeter and waiting 5 minutes.

⚠️ Warning: If you smell a sharp smell of chemistry or see smoke, stop working immediately, take the device out into an open space and fall asleep with sand or salt.

The retrieved battery must be disposed of properly, without throwing it into the general garbage, as it contains toxic substances. Examine the compartment for glue residues and carefully remove them so that the new battery lays flat and tightly on the case.

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The main safety rule is never to pierce or bend a lithium polymer battery, this ensures its fire.

Installation of a new battery and assembly of the device

Before installing a new battery, compare its dimensions and the location of the connector with the old sample - they must be identical. A new layer of double-sided tape (usually included or purchased separately) must be applied to the new battery to lock it into the case and prevent chatter that can lead to the break of contacts.

Carefully place the battery in the compartment, press it to lock and connect the plume until the characteristic click. Make sure the connector is up smoothly and without distortion, then you can start to reverse assemble the plastic frames and twist the screws. All screws must be tightly twisted, but without fanaticism, so as not to break the thread in the plastic racks.

Check if there are any extra parts left and make sure that all the plumes (display, cameras, buttons) are connected correctly, only after complete mechanical assembly and check the reliability of the mounts can the device be turned on for the first start and check the health.

• 🧹 Clean the dust compartment and residues of old glue before installation.
• 🔋 Activate the battery: after connecting, let the phone lie on charging 15-20 minutes before switching on.
• 🔩 Wrap the screws diagonally for even distribution of pressure.
• 👀 Visually check for no gaps between the screen and frame after assembly.

First start and calibration of the battery

After assembly, turn on the smartphone and wait for the MIUI operating system to load. If the device does not respond to the press of the power button, plug in the original charger and wait 10-15 minutes - the power controller could go into a deep sleep. The appearance of the Mi logo indicates a successful installation, after which you should check the charge indication.

To properly operate the system and display the real percentage of charge, it is recommended to conduct a calibration procedure, which consists of completely discharging the device before turning off, followed by charging to 100% when off, and repeating the cycle again, which will help the software correctly determine the capacity of the new cell.

In the first days of use, carefully monitor the heating temperature of the case and the discharge rate. If the phone is warming to a simple or quickly loses charge, you may have got a defective instance or the wrong train is connected, which requires redisassembly and diagnosis.