Replacement of the battery on Xiaomi Redmi 4X: a complete guide with photos and nuances

Xiaomi Redmi 4X (codenamed santoni) was released in 2017, but is still popular with users due to its reliability and low price. However, over time, even the best battery loses capacity: the phone starts to run out in a few hours, turns off at 20-30% charge or refuses to turn on. If you are faced with these problems, it is time to think about replacing the battery.

You can change the battery on the Redmi 4X either in the service center or on your own. The second option will cost less (the new battery costs from 500 to 1200 rubles), but it will require care and patience. In this article, we will discuss the entire process from tool preparation to testing a new battery, and also talk about typical errors and ways to avoid them. If you have never dismantled smartphones, do not worry: the design of the Redmi 4X is relatively simple, and we will highlight all the critical points separately.

Preparation: tools and components

Before you start disassembling, make sure you have everything you need, and even one tool can damage the body or internal components.

Main list:

• 🔧 Plastic blade (or mediator) to separate the back cover. Metal tools can't be used, they'll scratch the plastic.
• ⚙️ A cross screwdriver (size PH00 or PH0) is for screw twisting. Redmi 4X uses small screws, so the screwdriver must be accurate.
• 🔋 New battery -- Choose the original battery (article MB39) or the quality battery (such as Patona or Remax) and avoid cheap no-name batteries, which can swell or fail quickly.
• 🧲 Magnetic substrate or container -- so you don't lose the screws. Redmi 4X has 10 screws, but they're all different sizes.
• 🔥 Hair dryer or thermoair station - for softening the glue (optional, but simplifies the process).
• 📱 Suction cup - will help to lid if the glue is too strong.

Also, prepare your workspace: it should be clean, well-lit and without static electricity (a table with a wooden or plastic surface is ideal). Don't disassemble your smartphone on a carpet or couch - small parts can get lost, and static electricity will damage the motherboard.

If you buy a battery online, check its capacity: the original Redmi 4X battery has a capacity of 4100 mAh. Some sellers indicate inflated values (for example, 5000 mAh) is a fraud. Also pay attention to the date of production: the optimal battery age is not more than 6 months from the date of release.

Step 1: Turn off and disassemble the smartphone

The first and most important step is to turn the device off correctly, and in no case disassemble the phone when it's on, it can short-circuit and cause the motherboard to fail.

Instructions for switching off:

1. Press the power button for 5-7 seconds.
2. The menu will appear on the screen – select Turn Off (or Power Off).
3. Wait for a complete shutdown (vibration and charge indicator will go out).

If the phone doesn't respond to the power button (for example, because the battery is completely drained), plug it into charging for 10-15 minutes, then try again. If that doesn't work, you'll have to disassemble the device when it's off, but that increases the risk of damage.

We shall proceed to the disassembly:

1. Remove the tray for SIM- cards using a paper clip or a special key.
2. Heat the back cover with a hair dryer (~60°C) for 1-2 minutes. This will soften the glue and facilitate separation.
3. Insert a plastic blade into the gap between the lid and the body (start at the bottom edge where the connectors are located). Carefully drive the blade around the perimeter, separating the lid.
4. If the lid does not lend itself - use a suction cup, but do not apply excessive force so as not to break the latches.

⚠️ Warning: In Redmi 4X, the back cover is not only attached to glue, but also to plastic latches. If you hear a crunch, one of the latches is broken. It's not critical for the phone to work, but it can worsen the dust protection.

Step 2: Disconnecting the plumes and removing the battery

When you take the back cover off, you'll see the battery covered with black film, and you take it out, and you'll need to disconnect all the plumes and connectors first, so you don't damage the motherboard.

Procedure:

1. Unscrew 10 screws that hold the metal plate over the battery, and remember their location, they're of different lengths!
2. Carefully remove the metal plate and put it aside.
3. Disconnect the battery plume with a plastic blade, which is located at the top of the battery and is attached with a latch, and then pull it up, and then pull the connector out.
4. Disconnect the camera plumes, fingerprint sensor and display (if they interfere), and can be seen in the photo below.

Now we can start removing the battery, and in the Redmi 4X, it's glued to the body with double-sided tape, so that it can be removed.

• 🔹 Put a plastic shoulder blade on the battery from any angle.
• 🔹 Pull it up carefully while applying the glue. Don't use force -- if the battery doesn't respond, heat it with a hair dryer (maximum 70°C).
• 🔹 If the glue is too strong, use isopropyl alcohol (90%+): apply a few drops under the battery and wait 1-2 minutes.

⚠️ Warning: Do not use acetone or oil-based solvents to remove glue, which can damage the plastic parts of the case. Also, do not try to pull the battery out by putting metal objects on it, which can puncture the battery and cause fire.

Once the old battery is removed, check it for bloating. If it is deformed, do not try to puncture or compress it. Bloated batteries should be disposed of at special reception points (you can find them through the Ecosystem service).

Step 3: Installation of a new battery

Before installing the new battery, clean the seat of glue residues. Use a plastic spatula and a napkin soaked in isopropyl alcohol. Make sure the contacts are free of dust or oxidation - this can cause charging problems.

Next:

1. Remove the protective film from the new battery (if any).
2. Stick double-sided tape to the back of the battery. The original battery usually comes with new Scotch, but if it's not, use a quality analogue (e.g. 3M).
3. Carefully install the battery in place, combining contacts with the connector on the board.
4. Press the battery around the edges so that the scotch sticks well.

Now, connect the battery plume to the motherboard, and make sure the connector sits down to the stop — if it hangs around, the phone may not turn on or misidentify the charge level.

Once the battery is plugged in, put the metal plate back in place and twist all the screws. Don't pull them! In the Redmi 4X, the case is plastic, and excessive force can lead to cracks.

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Before you final build, turn on the phone without the back cover and check if the new battery recognizes. If you see a warning on the screen about an "unoriginal battery" - don't worry, this is normal for most analogues.

Step 4: Building the phone and testing

After installing the battery, it remains to collect the phone in reverse order:

1. Connect all disconnected plumes (display, cameras, fingerprint scanner).
2. Install the back cover, starting at the top, make sure all latches are in place.
3. Insert the tray for the SIM- card.

Turn on your phone and check:

• 🔋 Whether the charge level is displayed (should be ~50-80% if the battery is new).
• ⚡ Whether the phone is charging from the charger (use the original charger on 5V/2A).
• 📱 Is there any overheating (in the first hours of operation, the new battery may be slightly warm, but not hot).
• 🔄 Whether the fast charging function is working properly (if supported).

If the phone is not switched on:

• Check if the battery is tight.
• Make sure all screws are twisted (unpatched screws can cause short circuits).
• Connect your phone to charge for 10-15 minutes – the battery may be dead.

If the battery is discharged too quickly after replacement (for example, in 4-5 hours), the reasons may be as follows:

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If after replacing the battery, the phone is unstable (spontaneously restarts, does not hold a charge), most likely, the problem is a poor battery or damage to the plume, in which case it is better to contact the service.

Common Mistakes and How to Avoid Them

Even if you change the battery carefully, you can make mistakes that will cause your phone to break down, and here are the most common ones:

1. Damage to the plume of the display or camera

The plumes in the Redmi 4X are very thin and fragile. If you accidentally rip one of them, the image on the screen may disappear, or the camera will stop working. To avoid this, always disconnect the plumes behind special plastic tongues, rather than pulling the wires.

2. Mixed screws

The screws in the phone are of different lengths, and if you screw a long screw into a place that's meant for a short one, it can damage the motherboard, so you don't get confused, you can arrange the screws in order, or take a picture of their location before you unscrew them.

3. Use of metal tools

Metal blades or screwdrivers can make contact with a board or scratch the case. Always use plastic or wooden tools.

4. Incomplete power outage

If you forget to disconnect the battery plume before work, a short circuit can disable the power controller.Always make sure the phone is completely off and the battery is off.

5. Ingestion of dust or moisture

Even fine dust caught between the battery and board contacts can cause charging problems.Work in a clean room and don't touch the insides of the phone with wet hands.

⚠️ Warning: If after the battery is replaced, the phone stops turning on and the charge indicator doesn't burn, you've probably damaged the power controller, and in this case, self-repair is virtually impossible, you'll need a diagnostics center using a programmer.

How to prolong the life of a new battery

To keep the new battery lasting as long as possible, follow these guidelines:

• 🔌 Don't leave your phone on charge all night. Optimally charge to 80-90% and turn it off.
• 🌡️ Avoid overheating (do not use your phone in the sun or while charging for games).
• 🔄 Once in 2-3 month, perform a full discharge/charging cycle (from 0% to 100%) to calibrate the controller.
• 📵 Don't use cheap chargers - they can damage the battery.
• 📱 Disable unnecessary functions (GPS, Bluetooth, 4G) if they are not in use.

You can also use applications to monitor the battery status, such as:

• AccuBattery - shows the real capacity and wear of the battery.
• Battery Guru – tracks charging cycles and temperature.
• CPU-Z provides detailed information about voltage and current.

The average life of a lithium polymer battery is 2-3 years (or 500-800 charge cycles), and if you're keeping an eye on the battery, that can be extended to 4 years.

FAQ: Frequent questions about replacing the battery with Redmi 4X