Xiaomi Redmi 4X — One of the most popular budget smartphones of 2017, even though it doesn't last forever, and over time, the battery loses capacity, swells up, or needs to be replaced, but the manufacturer didn't provide easy access to the battery: the body is glued together, and the battery is soldered to the board. This means that it is almost impossible to extract it without special tools and knowledge.
In this article you will find a step-by-step instruction for dismantling Redmi. 4X, We'll look at the tools and critical warnings to help prevent damage to the phone, and we'll look at both mechanical extraction (for power users) and alternative ways to "reanimate" the battery without completely disassembling it. If you have never disassembled smartphones, it is better to contact the service center.
Important: Xiaomi Redmi 4X (codenamed santoni, it has a non-removable battery soldered to the motherboard, which means that it will require a heat-air or dryer soldering station to replace it, because a conventional soldering iron will not work because of the risk of overheating components. If the battery is swollen, but the phone is still working, do not postpone the replacement: lithium-ion batteries in this state can ignite.
Preparation for disassembly: tools and security measures
Before you start removing the battery, make sure you have everything you need, and the absence of at least one tool can cause permanent damage to the board or display.
- 🔧 Plastic mediators or shoulder blades (to separate the body without scratches).
- 🔥 Thermo-air soldering station (power 300-500 W) or building dryer with temperature adjustment.
- 🧲 Screen suction cup (helps to gently lift the display).
- ⚡ Multimeter (to check the voltage on the contacts of the battery after retrieval).
- 🛠️ Set of screwdrivers (cross-haul) PH00 and a flat 1.5 mm for Xiaomi screws).
- 🧴 Isopropyl alcohol 90%+ (Cleaning contacts and removing glue residues).
- 🧊 Thermopaste or thermal glue (for fixing a new battery).
Also, prepare the workspace: it should be well lit, without dust or static electricity. Use an antistatic bracelet or periodically touch a grounded metal object to avoid damage to the chips by discharge.
⚠️ Note: If the Redmi battery 4X If you're swelling, don't try to prick it, it could cause a fire or a chemical burn.
Step 1: Turn off the phone and remove the back cover
The first step is to completely shut down the power, and even if the phone doesn't turn on, the battery can keep the charge.
- Hold the power button for 10-15 seconds to make sure the device is turned off.
- If the phone is responding to charging (the indicator is on), wait until the battery is completely discharged.
- Extract. SIM-card and memory card (if installed) so as not to damage them when heated.
Now we're going to take the back cover off. 4X It's glued around the perimeter, so you'll need a thermo-air station:
- 🔥 Heat the edges of the body with a hair dryer (temperature 80–100)°C) for 1-2 minutes, evenly running along the seams.
- 🧲 Place the suction cup on the bottom of the screen (near the Home button) and gently pull upwards.
- 🔧 Insert a plastic mediator into the resulting gap and slowly lead it around the perimeter, separating the cover.
If the lid doesn't lend itself, don't force it too much -- there may be latches inside. Reheat and try again. Once you remove the lid, you'll see the motherboard, the battery and the plumes.
☑️ Preparation for the removal of the Redmi cover 4X
Step 2: Disconnect the plumes and battery from the board
Before you can remove the battery, you need to turn off all the plumes that go to the motherboard. 4X three:
- 📱 Display plume (the widest, located at the top of the).
- 🔋 Battery plume (thin, with red and black wires).
- 🎵 Dynamic/microphone plume (small, at the bottom).
Use a plastic blade or tweezers to detach, gently tuck the connectors, pull them not upwards, but sideways (perpendicular to the board), and if the plume is not moving away, check if there is a latch.
Now, let's get to the hardest part, which is battery despatch. 4X It's soldered to the payment at two points (plus and minus:
- Cover the screen and board with aluminum foil or heat-resistant material to protect them from overheating.
- 🔥 Heat the contacts of the battery with a hairdryer (temperature 250-300)°C) for 20-30 seconds.
- 🛠️ Carefully tuck the battery with a plastic spatula until the solder melts.
- Repeat heating if the battery is not separated.
⚠️ Warning: Do not heat the battery for more than 40 seconds in one approach - this can cause it to ignite.
What to do if the battery is attached to the body?
Step 3: Removing the battery and checking the board
Once we've soldered, the battery can remain glued to the body to remove it:
- Put a plastic shoulder blade on the battery from any angle.
- Slowly lead the shoulder blade along the body, separating the adhesive layer.
- If the battery is swollen, do not bend it - this can cause the shell to rupture.
After extraction, check the motherboard for damage.
- 🔥 Darkening or scorched areas (a sign of overheating during soldering).
- 💧 Corrosion (if the battery leaks).
- 🔌 Integrity of contact sites (if they have detached, restoration will be required).
If the board is clean, wipe it with isopropyl alcohol and let it dry. If there is damage, it is better to contact the service - self-repair can aggravate the problem.
| Sign. | Possible cause | Action. |
|---|---|---|
| The battery will blow up, but it does not leak | Natural wear of lithium-ion elements | Replacement with a new battery |
| The board has white plaque. | Corrosion from leaking electrolyte | Alcohol cleaning + circuitry |
| Contact areas have been detached | Overheating at soldering | Rebuilding tracks with soldering iron |
| The phone will not turn on after replacement | Short circuit or damage to the plume | Diagnosis of multimeter |
Step 4: Installation of a new battery
For Xiaomi Redmi 4X It will fit the battery with characteristics:
- 🔋 Capacity: 4100 mAh (original) or 4000-4200 mAh (similars).
- 🔌 Voltage: 3.85 V (nominal).
- 📏 Sizes: Must match the original (check before buying).
Before installing the new battery:
- Make sure the contacts on the board and battery are clean and not oxidized.
- Apply a thin layer of thermal paste to the back of the battery for better heat sink.
- Salt the battery to the board using low-temperature solder (soldering temperature not higher than 300)°C).
- Secure the battery with bilateral tape or heat glue.
After installation, connect the plumes in reverse order and check the phone:
- 🔌 Connect the charger - the charging indicator should light up.
- 📱 Try turning on your phone (hold the power button for 10-15 seconds).
- 🔋 If the phone is not turned on, check the multimeter voltage on the contacts of the battery (should be ~3.7–4.2).
💡
If after replacing the battery the phone discharges quickly, check the battery consumption in the settings (Settings) → Battery. It's possible that some app is consuming too much power. It's also recommended that you calibrate the battery: completely drain the phone, then charge it to 100% without interruption.
Alternative ways: what to do if you do not want to disassemble the phone
Physical battery removal is not always required, and if your goal is to extend the life of the battery or fix minor problems, try these methods:
- 🔄 Battery calibration: fully discharge the phone, then charge to 100% without turning off charging. Repeat 2-3 times.
- ⚡ Resetting settings: go to Settings → Additionally. → Recover and reset and select Reset.This can eliminate software errors that affect charge consumption.
- 🛠️ Replacement through service centre: if you're unsure of your skills, reach out to the pros.Average cost of replacing a battery at Redmi 4X — 1500–2500 rubles (2026).
If the battery is blown up, but the phone is still working, don't delay the replacement.
- 💥 Damage to the screen (due to pressure on the matrix).
- 🔥 ignite during overheating or mechanical action.
- 📵 Disable the motherboard (due to short circuit).
💡
If the battery is in Redmi 4X It's a big blow, but it's still on -- it's an emergency, every day you use it increases your risk of fire or breakdown, immediately turn off your phone and remove the battery (or call the service).
Frequent Mistakes and How to Avoid Them
Even experienced tycoons sometimes make mistakes when replacing a battery, and here are the most common ones and ways to prevent them:
| Mistake. | Effects of consequences | How to avoid |
|---|---|---|
| Overheating of ration fees | Detachment of contact sites, failure of microcircuits | Use a thermo-air station with precise temperature control (max. 300)°C) |
| Use of metal tools | Contact closure, battery puncture | Work only with plastic or wooden blades |
| Incomplete shutdown of plumes before soldering | Damage to the display or motherboard | Check all the connectors before heating |
| Installation of a battery of another capacity | Fast wear, incorrect operation of the charging controller | Buy a battery with parameters identical to the original |
Another common problem is that the phone doesn't turn on after the battery is replaced, and the reasons may be:
- 🔌 Poor contact on soldered joints (check multimeter).
- 📱 Display plume damaged (check connection).
- 🔋 Failed new battery (measure voltage).
- 🔥 Short circuit on the board (diagnosis is needed).
If you encounter this problem, do not try to turn on the phone repeatedly - this can aggravate the damage.