Disassembly Xiaomi Redmi 4X: how to carefully remove the battery at home

Replacing the battery with Xiaomi Redmi 4X is a challenge that every smartphone owner faces sooner or later. Even with careful use, after 2-3 years, the battery capacity drops by 30-40%, and the device begins to discharge in a few hours. Self-dismantling allows you to save on the service center, but requires accuracy: one wrong movement - and you can damage the plumes or the battery itself.

In this article, you will find a step-by-step photo guide, a list of necessary tools and critical nuances that are not covered in most guides, how to avoid typical errors (for example, a break in a flexible display cable), and what to do if the battery is glued to the case, and alternative ways to extract if there is no professional equipment at hand.

⚠️ Warning: Redmi 4X (codenamed santoni, it has a non-removable battery, soldered to the motherboard only by a connector, but fixed with double-sided tape, and forced unheated tearing can cause the battery to rupture or fire!

Preparation: tools and security

Before disassembling, make sure you have everything you need.

• 🔧 Plastic blades (2-3 (a) - for the separation of the back cover and the slinging of the plumes.
• 🔥 Hair dryer or thermo-air station - for softening the glue (temperature) 60-80°C).
• ⚡ Multimeter – to check the voltage at the battery terminals before disconnecting.
• 🧲 Magnetic mat or organizer - for fixing screws (in Redmi) 4X 12 pieces of different sizes!).
• 🛠️ The screwdriver. T4 — for the screws of the case and motherboard.

Important: Work on an antistatic mat or in a room with 40-60% humidity. Static electricity can damage the board chips. If you don't have a mat, touch a grounded metal object (such as a heating battery) with your hand before you start working.

Also prepare:

• 📦 Plastic screw container (sign it so as not to confuse it with other projects).
• 🧴 Isopropyl alcohol 90%+ — Cleaning contacts and removing glue residues.
• 🩹 Gloves and safety glasses in case the battery is swelled or damaged.

Step 1: Turning off and discharging the device

The first and most critical step is to turn off the power correctly, and not enough battery discharge can lead to short circuits when the plume is disconnected.

In the Redmi 4X, the battery connector has no back current protection - if you turn it off under load, it can burn the charging controller.

1. Turn off the phone with a long press on the power button.
2. Connect it to the charger and wait until the indicator goes out (the battery is discharged to 0%).
3. Turn off the charging and wait 10 minutes – this ensures that all the capacitors on the board will run out.

⚠️ Warning: If the battery is swelling (body cover is raised), don't plug the device into charging! The risk of fire is extremely high. Go straight to the dismantling, but work with gloves and outdoors.

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If the phone doesn't turn on but the battery isn't bloated, try "resuscitation": plug the charge for 30 minutes, then press Power + Volume up for 10 seconds. Sometimes this resets the power controller.

Step 2: Removal of the back cover

The Redmi 4X is glued around the perimeter, not fixed by latches, as in newer models, and it will require uniform heating to remove it.

Instructions:

1. Place the phone on a flat surface with the screen down.
2. Dryer warm the edges of the body around the perimeter (keep 5-7 cm away so that the plastic doesn't melt). Start at the bottom, there's less glue.
3. Insert a plastic blade into the gap between the lid and the middle frame (near the headphone jack) and carefully guide it along the case.
4. Once the lid starts to move away, don’t pull it sharply – underneath it are the plumes of the fingerprint scanner and NFC antennas (if any).

📌 Tip: If the lid doesn't lend itself, don't increase the temperature of the hair dryer. 2-3 time-to-time 30 Overheating can warp plastic or damage the display.

Heated body perimeter | Prepared plastic blade | All cables (USB, headphones) Disconnected | The phone lies on a soft surface-->

Step 3: Disconnecting the plumes and batteries

Once you take the lid off, you'll see the motherboard, the battery and a few plumes, and the first rule is, turn off the battery first, then everything else.

Procedure:

1. Unscrew 4 screws fixing the metal plate above the battery connector (they are marked with red circles in the photo below).
2. Carefully slap the plate with a spatula and remove it.
3. Disconnect the battery connector with a plastic spatula (not metal!) and pull by the black tongue, not the connector itself.
4. Check the multimeter voltage at the battery terminals - it should be 0 V. If it shows 3.7-4.2 V, then the battery is not discharged to the end (go back to Step 1).

Now you can turn off the other plumes:

• 📱 Display plume (the widest, at the top of the board).
• 🔍 Camera plume (thin, next to the top speaker).
• 👆 Power and volume button plume (small connector in upper right corner).

⚠️ Attention: The fingerprint scanner plume (if any in your model) is glued. Don't pull it by force - gently shovel it on the side.

Step 4: Remove the battery

The battery in the Redmi 4X is glued with double-sided tape to the back cover. Never try to pull it out by force, which can tear the shell and cause electrolyte leaks.

Safe way:

1. Put the battery with a plastic blade from the upper right corner (there is less glue).
2. Pull up carefully – if resistance is strong, stop and warm up this zone with a hairdryer (60°C).
3. Put a thin plastic card (for example, a bank card) under the battery and drive it along the case, separating the glue.
4. If the battery is swollen, don't pierce it! Take it out as carefully as possible, even if it takes 20-30 minutes.

🔧 Alternative method (if the glue is very strong):

• Apply a drop of acetone (only on glue, not on battery!) and wait 5 minutes.
• Use a string or guitar string, running it under the battery and sawing movements separate the scotch.

Step 5: Installation of a new battery

Before installing a new battery, clean the seat of glue residue with isopropyl alcohol. Do not use acetone - it can damage the plastic of the housing.

Installation instructions:

1. Remove the protective film from the new battery (if any).
2. Stick double-sided tape (complete with battery) onto the case. Do not use superglue or heat-glue!
3. Carefully put the battery in place, combining the connector with the connector on the board.
4. Connect the battery connector last, after all the other plumes.

⚠️ Note: If you are installing a larger battery (e.g., 4,000 mAh instead of the standard 4100 mAh), check its physical dimensions. Even a minor mismatch can lead to pressure on the screen or body.

After assembly:

• 🔋 Charge your phone to 100% and discharge to 0% 3 times in a row – this calibrates the battery controller.
• 📊 Check the capacity in the engineering menu (#4636## → "Battery information").

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A new battery may have an incorrect percentage of charge for the first 2-3 cycles, which is normal because the controller needs time to adjust.

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when replacing the battery with a Redmi 4X.

• 🔌 Disconnection of the display plume to the battery → The risk of short circuit is always the battery first!
• 🔥 Battery overheating with a hairdryer → It can cause electrolyte leakage: 60-80°C.
• 🧲 Loss of screws → Use a magnetic organizer. Rotors of different lengths, they can't be confused!
• 📉 Use of a non-original battery → It might not hold a charge or it might swell in a month.

How to check the originality of the battery?

• The case should have a hologram of Xiaomi and a serial number.
• Capacity is listed as 4100 mAh (not 4000 or 4200!).
• The connector has gold contacts, not copper contacts.

💡 Tip: If the phone does not turn on after replacement, check:

• Is the power button plugged in (frequent error!)
• Are the battery contacts closed (call the multimeter)?
• Has the overheating protection worked (wait 10 minutes and try again)

FAQ: Answers to popular questions