Replacement of battery in Xiaomi Redmi 4X: a complete guide with photos and videos

Why the Redmi 4X Battery Fails and When to Change It

Xiaomi Redmi 4X (codenamed santoni) was released in 2017, and even with careful use of its battery capacity of 4100 mAh after 3-5 years begins to lose capacity. Typical signs of wear: the phone discharges in a couple of hours, turns off at 20-30% charge or does not hold a charge after connecting to charging. If your Redmi 4X became “voracious”, do not rush to blame the firmware – in 90% of cases the problem lies in the degraded battery.

The manufacturer claims that lithium-polymer batteries are designed for 500-800 charging cycles, but the real life depends on the operating conditions. Overheating, deep discharges (below 5%) and the use of low-quality chargers accelerate wear. For example, if you regularly played heavy games with a connected charger, the battery could degrade after 2 years, in which case replacement is the only way to restore the smartphone to its previous autonomy.

How do you know if you need to change your battery?

• 🔋 The phone discharges by 50% in 1-2 hours without active use.
• 🔌 When connected to a charge, the percentage of charge “jumps” (for example, from 10% to 40% and back).
• 🔥 The body heats up in the battery area even with minimal load.
• ⚡ The smartphone turns off at 15-30% charge and turns on only after connecting to the network.
• 📉 In settings (Settings) → Battery → Battery condition) capacity shows less than 70% of the original.

Which battery to choose for Redmi 4X: original vs analogues

The original battery for the Redmi 4X has an MBJ406450 and a capacity of 4100 mAh. However, after 2020, Xiaomi officially stopped supplying spare parts for this model, so the market is dominated by analogues from third-party manufacturers. The main rule: avoid batteries with overcapacity (for example, "5000 mAh") is a marketing fraud, and the real characteristics of such batteries are often worse than the original.

Here are the proven options for replacement:

When buying, pay attention to:

• 🔍 Availability of a charge controller – cheap batteries without it can swell or fail.
• 📦 Set: the set must have adhesive strips for fixing the battery.
• 📅 Production date: optimal if the battery is not more than 6 months.
• 🛡️ Guarantee: Reliable sellers give a minimum of 6 months.

⚠️ Warning: Don’t buy batteries with AliExpress for too low a price (less than 800) ₽). Often these are fakes with a real capacity of 2000-2500 mAh, which will last for six months.

Battery Replacement Tools: What You Need

You don't need professional tools to replace your battery on your own in the Redmi 4X, but you can't do without a minimum set.

• 🔧 Plastic blades (mediators) - for careful smearing of the body and disconnection of plumes.
• ⚒️ The screwdriver (PH00 or PH0) — screw-off.
• 🧲 Magnetic mat or container – to avoid losing small details.
• 🔥 Hair dryer or thermoair station - for softening the glue (optional, but simplifies the process).
• 📱 New battery - with adhesive strips in the kit.
• 🧴 Isopropyl alcohol (90%+) — glue-residue.
• 🔌 Tweezers - for working with small connectors.

If you do not have experience disassembling smartphones, we recommend you to purchase a special repair kit (costs about 500-800). ₽ It's usually all the tools you need, including a screen suction cup.

⚠️ Warning: Do not use metal blades or knives, they can damage plumes or body. Plastic mediators are safer, even if the process takes longer.

Turn off the phone and remove it. SIM-memory-card|Charge your smartphone to at least 30% (in case you need to turn it on in the process)|Prepare the workplace: clean desk, good lighting|Take a picture of each step of the dismantling (useful when assembling)|Turn off power for 10-15 minutes before starting (discharge static electricity)-->

Step-by-step: how to disassemble the Redmi 4X and replace the battery

The process of replacing the battery in the Redmi 4X takes about 30-60 minutes, the main thing is to take your time and follow the instructions. Below is a step-by-step algorithm with photos and videos (see at the end of the section).

Step 1: Removing the back cover

1. Turn off the phone and remove the tray for SIM-map.

2. heat the hair dryer back cover around the perimeter (temperature ~60 ° C) for 1-2 minutes - this will soften the glue.

3. Insert the plastic blade into the gap between the body and the cover (start at the bottom edge where the charging connector is located).

4 Carefully swipe the lid along the hull, separating the lid. If you feel resistance, warm up the place again with a hairdryer.

Important: Don't put too much effort into it -- there are antenna plumes and turn-on/volume buttons under the lid, and if the lid doesn't lend itself, warm up the glue again.

Step 2: Disconnect the plumes and remove the battery

1 Unscrew 10 screws that fix the metal plate (they are of different lengths - remember where it was!).

2 Take off the plate and disconnect the battery, screen and motherboard plumes, and gently put a plastic blade on them.

3. Under the battery, you'll see two black plumes -- these are adhesive strips. Pull them at the same time to separate the battery from the body. If the strips break, put a spatula on the battery (carefully not to puncture!).

Critical: Do not bend the battery or pierce it - it can lead to fire or explosion.

Step 3: Installation of a new battery

1. Remove the remnants of old glue from the case (use isopropyl alcohol and a napkin).

2. glue new strips (go with the battery) to the body.

3. Connect the plume of the new battery to the motherboard.

4. Put the battery back in place and press it to make the glue catch.

Step 4: Assembly of the phone

1. Connect all the plumes back (first the battery, then the screen, then the motherboard).

2. Set the metal plate and twist the screws.

3. Stick the back cover. To be reliable, warm it up with a hair dryer and press it for 1-2 minutes.

After assembly, turn on the phone and check:

- Is the battery charging?

Whether the volume and inclusion buttons are working;

- I'm not overheating.

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If the battery is discharged quickly after replacing, calibrate: completely discharge the phone, then charge to 100% without interruptions. Repeat the procedure 2-3 times.

Frequent Battery Replacement Mistakes and How to Avoid Them

Even with careful disassembly, beginners often make mistakes that cause their phone to break, and here are the most common ones and ways to prevent them:

• 🔌 Screen plume damage occurs when you're slobbering around in a careless timber with a spatula. Solution: Use thin plastic mediators and take your time.
• 🔋 The battery puncture -- if the battery is swelling, it's easy to pierce. Solution: don't press the battery, pull the sticky strips.
• 🔧 Loss of screws - screws at Redmi 4X Solution: use a magnetic mat or a container with cells.
• 📱 Improper assembly -- if you forget to plug in the antenna plume, the network signal will deteriorate. Solution: photograph each step of disassembly.
• 🔥 Overheating when soldering - if you solder the contacts of the battery, you can damage the motherboard.Solution: use a soldering iron with temperature adjustment (max. 300)°C).

Another common problem is that the phone doesn't see the new battery.

• Bad contact of the plume (check if it sits tightly in the connector).
• Faulty charge controller on the motherboard (diagnosis is needed).
• Failed battery (try connecting the old one – if it is identified, the problem is in the new one).

⚠️ Warning: If the battery swells during the first few days after replacing it, immediately turn off the phone and remove it.

How to prolong the life of a new battery: tips for operation

To make the new battery in the Redmi 4X last longer, follow these guidelines:

• 🔋 Avoid full discharge – recharge your phone at 10-20% charge.
• ⚡ Don’t use “fast charging” – Redmi 4X Does not support Quick Charge, and cheap high-current charges reduce battery life.
• 🌡️ Control the temperature – do not leave your phone in the sun or near heat sources.
• 📵 Disable unnecessary functions — GPS, Bluetooth and mobile data in the background consume charge.
• 🔄 Calibrate the battery – once every 2-3 months perform a full cycle of discharge / charging.

It is also useful to disable auto-update applications and background activity for unnecessary programs. To do this, go to Settings → Battery → Battery Optimization and select Power Saving mode.

If you use custom firmware (like LineageOS), check the kernel settings — some governess (like performance) increase the load on the processor and, as a result, battery consumption. The best option for autonomy is ondemand or conservative.

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Regular calibration of the battery and avoiding extreme temperatures (below 0°C and above 40°C) can increase its lifespan by 20–30%.

Should I change the battery myself or contact the service?

Replacing the battery in the Redmi 4X is a medium-sized task. If you have experience disassembling equipment (like changing the screen or cleaning your laptop), you can do it yourself. However, if you've never held an electronic screwdriver in your hands, you better contact the service. Here's a comparison table:

If you decide to use the service, choose a vetted workshop with reviews. Ask what battery they install and ask for a warranty of at least 3 months. The average replacement price in the service is 1800-2500. ₽ (spare-part).

Self-replacement is cheaper, but requires care, and if you’re not confident, practice on an old, unwanted phone or watch YouTube video showdowns (like from Fixez or Repair Universe channels).

FAQ: Answers to Frequent Questions About Battery Replacement in Redmi 4X