Why Xiaomi Mi 4X Battery Fails and When to Change It
Xiaomi Mi 4X (also known as Redmi 4X in some regions) is a popular 2017 model that is still used by many users. However, even when handled carefully, lithium-ion batteries degrade over time: their capacity decreases by 20-30% after 2-3 years of active use. If your Mi 4X starts to discharge in a few hours, shut down at 20-30% charge or overheat during charging, it’s time to think about replacing the battery.
In this article, we will discuss how to change the battery on Xiaomi Mi 4X without going to the service center. You will learn what tool you need, how to properly disassemble the smartphone, what mistakes beginners most often make, and how to check the new battery after installation, and we will give recommendations on choosing a quality battery and tell you whether to save on cheap analogues.
⚠️ Important: Replacing the battery is a procedure that requires care. Wrong actions can damage the plumes, the display, or even the battery. If you are not confident in yourself, you should contact the professionals.
Signs that Xiaomi Mi 4X battery needs replacement
How do you know if the battery is the problem, not the software or the charger?
- 🔋 The smartphone discharges in 3-4 hours with moderate use (previously held the day).
- 🔥 The phone gets very hot during charging or working.
- ⚡ Charge jumps (for example, from 40% immediately drops to 15%).
- 🛑 The device turns off at 20-30% charge and does not turn on without connecting to the network.
- 📉 Autonomous life has decreased by 2-3 times compared to the new state.
- 🔌 Charging is extremely slow or interrupted.
If you see at least 2-3 of these signs, the battery is 90 percent likely to wear out, and you can check the battery status with applications like AccuBattery or AIDA64 before you replace it, and they'll show you the actual capacity and the degree of wear.
⚠️ Warning: If the battery is swollen (the body of the smartphone has deformed), immediately disconnect the device and do not use it.The bloated battery can damage internal components or even ignite.
What battery to choose for Xiaomi Mi 4X: original vs analogues
The original battery for Xiaomi Mi 4X is marked BM43 and a nominal capacity of 4100 mAh. However, there are many analogues on the market, which may differ in quality and durability.
| Type of battery | Capacity | Pluses | Cons | Price (2026) |
|---|---|---|---|---|
| The original (Xiaomi) | 4100 mAh | Guaranteed quality, exact compliance with parameters | Expensive, hard to find on sale | 2500–3500 ₽ |
| Licensed analogue (e.g. Patona, Remax) | 4000-4200 mAh | Good price/quality ratio, widely available | It may be less than the original. | 1200–2000 ₽ |
| Budgetary analogue (no-name) | 3800-4100 mAh | Low price, quick delivery | Low quality risk, rapid wear and tear | 600–1200 ₽ |
| Increased capacity (unofficial) | 5000–6,000 mAh | Holds the charge longer | May not fit into the body, the risk of overheating | 1800–3000 ₽ |
Our advice is that the best choice is licensed analogues from proven brands, cheaper than the original, but still pass quality control. Avoid batteries that are too cheap (below 800). ₽) — They often have an understated real capacity and can damage your smartphone.
When buying, pay attention to:
- 📦 Presence of factory packaging and hologram.
- 🔍 Conformity of marking (BM43 for Mi 4X).
- 📅 Production date (battery freshness no older than 6 months).
- 🛡️ Guarantee from the seller (minimum 6 months).
💡
Check the reviews of the seller on the site before you buy, often under the guise of original batteries, fakes with low capacity are sold.
Preparing for replacement: security tools and measures
To replace the battery with Xiaomi Mi 4X, you will need:
- 🔧 Screwdrivers: Phillips #00 (cross) and Pentalobe P2 (starlet).
- 📱 Plastic blades or mediators for disengaging the body.
- 🔥 Hair dryer or thermo-air station (for softening glue).
- 🧲 Magnetic mat or screw tray.
- 🩹 Alcohol wipes for cleaning contacts.
- 🔋 New battery (pre-tested multimeter).
- 🛠️ Suction (optional, for tweaking the screen).
Also prepare the workplace:
- 🪑 Clean table with good lighting.
- ⚡ Antistatic bracelet (or touch grounded metal objects regularly).
- 📸 Take a picture of the disassembly process – this will help to assemble the smartphone back.
⚠️ Warning: Do not replace the battery in high humidity or near open fire. Lithium-ion batteries are sensitive to static electricity and mechanical damage.
Turn off your smartphone and remove it. SIM-map|Battery discharge to 20-30% (for safety)|Prepare all the tools and a new battery|Wear an antistatic bracelet or discharge static electricity|Check the integrity of the new battery (whether there is swelling or damage)-->
Step-by-step: how to disassemble Xiaomi Mi 4X and replace the battery
Now, to the process itself, follow the instructions carefully so that you don't damage the plumes or the display.
Step 1: Disconnect and heat the body
1. Turn off your smartphone and remove the tray for SIM-map.
2. Heat the hair dryer around the perimeter for 2-3 minutes (temperature ~60 ° C). This will soften the glue that glues the battery and body.
3. Carefully apply a plastic blade gap between the body and the screen, starting from the lower edge (near the charging connector).
Step 2: Removal of the back cover
1. Continue to carefully separate the lid as you move around the perimeter. Use a suction cup if the lid fails.
2 Don't put too much effort into it, there may be latches inside. If the lid doesn't come off, warm it up again with a hair dryer.
3. Once you remove the lid, you'll see the battery covered with black film and the plumes.
Step 3: Disconnecting the plumes and removing the battery
1 Unscrew 4 screws that fix the metal plate above the plumes (use Phillips screwdriver #00).
2. Gently disconnect the battery plumes, display and camera with a plastic blade.
3. Put the battery on a plastic card starting at the top edge. If it is glued, warm it up with a hair dryer (no more than 1 minute).
4. Remove the old battery. If it's swelling, don't pierce it or bend it.
Step 4: Installation of a new battery
1. Clean the contacts of the new battery and the connector on the board with an alcohol napkin.
2.Put the battery in place, making sure that the plume is not twisted.
3. Connect the battery plume to the motherboard.
4. fasten the battery to double-sided scotch (usually included).
Step 5: Build a Smartphone
1. Connect all the plumes back (display, camera, buttons).
2. Set the metal plate and twist the screws.
3. Press the back cover until the snap of the latches. If necessary, warm it up with a hair dryer for better fixation.
4. Turn on your smartphone and check the new battery.
What if the smartphone does not turn on after replacement?
Frequent battery replacement errors and how to avoid them
Even experienced users sometimes make mistakes that can cause a smartphone to break, and here are the most common ones:
- 🔧 Using metal tools to tweak the battery, which can puncture the battery and cause a short circuit. Always use plastic blades.
- 🔥 Battery overheating with a hairdryer. Temperature above 70.°C can damage the battery. Keep the hair dryer at a distance of 10-15 cm.
- 🔌 Incorrect connection of the plumes. If the display does not work after assembly, check if the plume sits tightly in the connector.
- 📱 There's a lot of pressure on the screen when you build it, and it can damage the matrix or the oleophobic coating.
- 🔋 Using a battery with inadequate capacity: a 5,000 mAh battery may not fit into the case or overheat.
Another common problem is that the smartphone doesn't see the new battery, and it can be because of:
- Bad contact of the plume (check if it is bent).
- Failure of the power controller on the board.
- Battery defective (check the voltage with a multimeter - should be ~3.7-4.2V).
💡
If the battery is quickly discharged after replacing the battery, calibrate the battery: completely discharge it, then charge it to 100% without interruption. Repeat the procedure 2-3 times.
Calibration of the new battery and its care
To make the new battery last longer, you need to calibrate it properly and operate it.
- Use your smartphone before you automatically turn off, then charge to 100% without interruption.
- Recalibrate: Repeat the procedure 2-3 times in the first days after replacement.
- Avoid extreme temperatures. Do not leave your smartphone in the sun or in the cold (optimum: 10-35 ° C).
- Use the original charger. High-current charges (fast charging) shorten battery life.
- Don't keep your smartphone on charge all the time. After 100%, disconnect it from the network.
We also recommend turning off background processes that drain the battery quickly:
- 📱 Turn off auto-update apps in Settings → Annexes → Autoboot.
- 📡 Reduce the time of network search in Settings → SIM-maps and mobile networks → Searching the net.
- 🔍 Turn off the constant synchronization of accounts (Google, Mi Account).
With proper care, the new battery will last 2-3 years without a noticeable loss of capacity.