Xiaomi Redmi Note 4X is deservedly considered one of the most reliable models in the history of the brand, thanks in large part to the legendary Snapdragon 625 processor and a huge battery. However, time spares no one, and even the most capacious lithium polymer battery loses its original capacity over time. If your device begins to run out in a couple of hours or suddenly turn off when charged 20-30%, it’s probably time to think about replacing the battery.
Many users are afraid to open modern gadgets, fearing damage to fragile plumes or to break the tightness of the case. Indeed, replacing the battery requires a certain accuracy and a minimum set of tools, but this process is quite possible for a person with “straight hands”. It is important to understand that self-repair will not only save the budget, but also allow you to install a quality original part, rather than a cheap analogue that is often offered in service centers.
In this article, we will go into detail about the entire process, from the preparation of the workplace to the final calibration of the new battery, you will learn how to safely unplug the back cover without damaging the glass, how to properly disable the plumes and why the first charge of the new battery must last at least 8-10 hours for the correct calibration of the controller. Let's give your smartphone a second life.
Diagnostics and selection of a new battery
Before you start disassembling, make sure that the problem lies in the physical wear of the battery, not software failures or background processes. Check the power consumption statistics in the Settings → Battery menu. If the discharge schedule looks linear and predictable, but the run time has decreased by many times, this is a clear sign of degradation of the chemical composition. Also note the appearance: bloating of the case or detachment of the back cover is a critical signal that requires immediate intervention.
When choosing a new battery for the Redmi Note 4X The market is saturated with counterfeits, which may have a declared capacity of 4100 mAh, but in fact have half the size. BM46 or BN41 (depending on the audit fee, paying attention to the presence of holograms and QR-A high-quality Li-Po battery must have clear labeling, flat edges and no solvent odor.
It's also worth checking the condition of other components while the phone is disassembled, often with the battery, and the adhesive cap locks are changed to ensure a tight fit, using old adhesive strips can cause the back panel to fall off or fall off in your pocket.
⚠️ Warning: Never use a ballooned battery! A puncture or severe deformation of such a battery can cause fire or chemical burn. If the battery is swelling, remove it as carefully as possible without pressing on the center.
You can use an engineering menu or special applications to accurately determine your battery model, but a physical examination after opening will give 100% of the result.
Tools and workplace preparation required
Quality repairs begin with the proper organization of the space. You need a clean, well-lit desk, preferably with antistatic coating or a regular wooden surface. Do not work on carpet or synthetic fabric, as static electricity can damage the sensitive electronics of the smartphone. Prepare all tools in advance so that you do not get distracted during the dismantling process.
The basic battery replacement kit in the Xiaomi Redmi Note 4X includes the following items:
- 🔧 Set of screwdrivers (cross-haired) Ph0, Ph00 Torx T5) — cock-wheel.
- 🔥 A hair dryer or thermophen (you can use a powerful hair dryer) - to soften the glue under the back cover.
- 💳 Plastic card or special spatula (pry tool) - for neat opening of the body without scratches.
- 🧲 Magnetic mat or sheet of paper with markup – so as not to lose tiny screws of different sizes.
- 🧴 Clay. B-7000 or bilateral tape - for the final sealing of the body.
Pay special attention to heating. The glass on the back of the Redmi Note 4X is heated unevenly, so it's important to warm the perimeter, not the center. Overheating can damage the display on the back side or detach the oleophobic coating if you warm it too long. The optimal heating temperature is about 80-90 degrees when the body gets hot, but the finger is still resistant.
Before you start, you should turn off your smartphone. Even if it's off, there's still some residual current on the board, so when you remove the back cover, the first thing you need to do is turn off the battery plume from the motherboard. That's the golden rule of electrical safety when you repair mobile devices.
☑️ Ready for repair
Rear cover removal process
The most critical stage where errors are most common is to separate the glass back from the metal frame. Glass is fragile, and if you open it sloppy, it can crack. Heat the body perimeter with a hairdryer for 2-3 minutes, constantly moving the flow of hot air. Don't keep the hairdryer at one point for too long.
After heating, insert a plastic blade or suction cup into the bottom end, where the charging connector normally resides. Tuck the lid carefully, creating a small gap. Push the blade along the faces, cutting the adhesive layer. Movements should be sliding, parallel to the plane of the screen, not perpendicular to it, so as not to damage the display module.
Some Redmi Note 4X versions may have an extra plastic plate under the lid covering the bottom, which you also need to gently flick off, and if the lid doesn't lend itself, don't use brute force, you better heat it up again, and the glue should be elastic.
⚠️ Attention: Be extremely careful at the top of the smartphone, where the plume of the main camera module and the fingerprint scanner passes, and sudden movement or deep immersion of the shoulder blade can interrupt these delicate components.
After successfully removing the lid, you will see the smartphone’s internal device open up, and you will see a large black battery that occupies almost 70% of the volume, a motherboard at the top and a daughterboard with a charging connector at the bottom.
Replacement of the battery and assembly
The battery in Xiaomi Redmi Note 4X is fixed to double-sided tape, and just take it off. Under the battery there is also a plume connecting the lower board to the main one, so you can not pull it from the bottom up categorically. First you need to unscrew the protective metal plate that covers the connectors of the battery (usually 4 screws).
After removing the plate, carefully disconnect the battery plume. Now you need to remove the battery itself. For this, it is best to use special stretching strips (if there are any under the battery) or gently smear it with a plastic blade, starting from the bottom. If the battery is sitting very tight, you can warm the body a little in the battery area with a hairdryer, but very carefully.
Install the new battery, making sure the connector is flat. Connect the plume to the motherboard before the characteristic click. Set a metal protective plate and twist the screws. It is important not to drag them over, so as not to break the thread in the aluminum case.
The assembly process follows in reverse order:
- 🧹 Clean the frame of the case of the remnants of old glue with an alcohol napkin.
- 🧴 Apply a thin layer of glue B-7000 around the perimeter of the frame or use new adhesive strips.
- 📱 Carefully apply the back cover, combining all protrusions and holes.
- ⏳ Press the lid with rubber harnesses or put under the press (heavy book) on 1-2 half-hour.
Don't turn the phone on immediately after gluing, let the sealant grab. Complete polymerization of the glue takes about 24 hours.
What if the phone doesn’t turn on after replacement?
Comparison of characteristics: Original vs Copy
Understanding the difference between a quality substitute and a genuine fake will help you keep money safe and secure, and here is a table showing the key differences to look out for when buying.
| Parameter | Original / Quality analogue | Cheap copy |
|---|---|---|
| Weight. | Corresponds to the stated (about 80-90 g) | It is much easier (savings on materials) |
| Marking | Clear, laser engraving, there is QR-code | Lubricated seal, sticker, no codes |
| Jack | Tight fit, golden contacts | Luft plume, oxidized contacts |
| Behavior | Stable work, honest capacity | Charge jumps, fast discharge to standby |
Using a poor-quality battery can lead not only to poor autonomy, but also to the failure of the power controller on the motherboard. Savings of 300-400 rubles when buying a spare part can result in expensive repairs of the board.
Always require a battery warranty. An honest seller gives a minimum of 14 days to check, as the marriage sometimes only manifests itself in the process of operation.
💡
Buying a battery from trusted suppliers with a warranty is an investment in the safety and stability of your Xiaomi Redmi Note 4X, which will pay off with a long life.
Calibration and first launch
After the battery is successfully replaced and the body is assembled, you need to correctly conduct the first charge cycle, which is necessary to calibrate the controller so that the Android system correctly displays the percentage of charge, and if you miss this step, the phone can show 100%, turn off 20% or charge with jerks.
The initial calibration procedure is as follows:
- 🔌 Connect the phone switched off to the original charger.
- ⏱ Leave it to charge until the indication. 100% (more 1-2 hour after).
- 📱 Turn on the phone without turning off charging, and make sure the system shows full charge.
- 📉 Discharge the device completely until it is automatically turned off in normal use mode.
- 🔋 Put on charging up to 100% without interruptions.
After this cycle, the power controller will remember the real capacity of the new cell, in the future the smartphone will work steadily, and the indicator readings will be accurate, and it is recommended to also update the firmware to the latest version of MIUI, since new versions of the software often contain energy optimization.
⚠️ Warning: Do not use your phone during the first long charge for gaming or watching videos. The heating combined with the active chemical process in the new battery can negatively affect its life.
If after calibration problems with displaying the charge persist, it may be a problem in the software or the connector itself.