Xiaomi Redmi 4X (codenamed santoni) is one of the most popular budget smartphones of 2017, but after 5-7 years of operation, its battery inevitably loses capacity. If your device discharges in a couple of hours, turns off at 20-30% charge or the case is swollen, it’s time to replace the battery. In this article, we will discuss how to do it yourself without damaging the phone and without losing the warranty (if it is still valid).
The procedure does not require a soldering iron or special skills, but it will require care: improper disassembly can lead to damage to the plumes, detachment of the display or even short circuit.We will describe in detail every step from choosing a new battery to testing after installation, and also reveal the hidden pitfalls of the Redmi 4X model, which are not written in the standard instructions.
When exactly do I need to replace the battery?
Take your phone apart at the first sign of a quick discharge, sometimes it's software failures or apps' background power consumption, and the following symptoms indicate that you need to replace your battery:
- 🔋 The phone turns off when the charge is above 15% (even after calibration).
- 📉 Bloating of the body: the screen or back cover rose, gaps appeared.
- ⚡ Battery heats up to 45°C+ charging or simple.
- ⏳ The operating time from full charge has been reduced to 3-4 hours (in standard use).
- 🔌 Charging is interrupted or jerked (may indicate damage to the battery controller).
If you see at least 2-3 items from the list, the diagnosis is obvious. For a precise check, use applications like AccuBattery (will show real capacity) or enter the code # #4636## in the engineering menu, then select Battery Information. A healthy Redmi 4X battery should show a capacity close to 3800-4000 mAh (original - 4100 mAh).
⚠️ Warning: If the battery is swelling, don't delay replacement! The risk of damage to the display or short circuit (with possible fire) increases significantly.
What battery should I use for the Redmi 4X?
Xiaomi’s original Redmi 4X battery pack (Article MBJ417450) is no longer in production, but there are quality batteries on the market, and the key is to avoid counterfeits with low capacity or low-quality controllers.
| Parameter | Optimal value | What to check |
|---|---|---|
| Capacity | 4000-4200 mAh | Fakes often indicate 5,000+ mAh is a scam. |
| Tension. | 3.85V (nominal) | It must match the original (check the label). |
| Controller | With built-in protection against KZ | The controller board must have a chip (e.g., TI BQ27541). |
| Compatibility | Only for the Santoni | Check with the seller: the battery for the Redmi 4/4A/4X is different! |
| Guarantee | 6 months. | Reliable sellers give a guarantee on batteries. |
Recommended brands of analogues:
- 🔝 ZMI (Xiaomi subsidiary – the best price/quality ratio.
- 🔋 Baseus – batteries with enhanced protection against overheating.
- 🛡️ Patona – German brand, 12 months warranty.
- 💰 Original used - only if the seller provides a photo of the test capacity.
The cost of a new battery for the Redmi 4X in 2026 is from 800 to 2500 rubles, depending on the brand. Buy only from trusted sellers (for example, AliExpress with a rating of 98% +, Beru, Svyaznoy). Avoid batteries without labeling or with inscriptions like "Super Capacity" - it is 100% fake.
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Before you buy, ask the seller to send a photo of the battery with a capacity tester (for example, the ZKEtech EBC-A20), which will eliminate cheating with understated mAh.
Replacement tools: what you will need
The Redmi 4X doesn’t need expensive tools to disassemble, but it doesn’t need them.
- 🔧 Plastic blades (2-3 pieces) - for separation of the cover and plumes.
- ⚒️ Cross screwdriver (size) PH00) — hull-rotor.
- 🔥 Dryer or thermo-air station - for softening the glue (temperature 60-80)°C).
- 🧲 Magnetic mat or container – so as not to lose screws.
- 📦 Suction - will help to adjust the screen (optional).
- 🧴 Isopropyl alcohol (90%+) — glue-residue.
- 🔋 Multimeter – to check the voltage of the new battery before installation.
If you don't have a hair dryer, you can use hot water in the bag (apply it to the back cover for 2-3 minutes), but this method is less reliable. It also comes in handy with a plastic card instead of a shoulder blade, but it can scratch the case.
⚠️ Attention: Do not use metal blades or knives! They can puncture the battery or damage the plumes. If the battery is swelling, do not heat it with a hairdryer (risk of fire.
Turn off the phone and remove it. SIM-map|Make a backup copy of the data|Charge your phone to 30-50% (for safety)|Prepare a workplace with good lighting|Wear an antistatic bracelet (optional)-->
Step-by-step: how to disassemble the Redmi 4X and replace the battery
Now, to the most critical point, follow the instructions carefully, because one wrong step can knock your phone out.
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 for 1-2 minutes (keep at a distance of 5-7 cm, so as not to overheat).
3. Insert a plastic blade into the gap between the lid and the body (start at the lower right corner where the SIM tray is). Carefully drive the blade along the edge, separating the lid. If the glue does not lend itself, warm up more.
4. When you take the lid off, put it aside, and underneath it you'll see the battery, the motherboard, and the plumes.
Step 2: Disconnect the plumes and remove the battery
1 Unscrew 11 screws (marked in the photo below) with a PH00 cross screwdriver. Rotors of different lengths - remember where you were!
2. Gently disconnect the plumes:
- Battery plume (red connector).
- Display plume (black, top).
Power/Volume button plume (optional if it interferes).
3. Put a plastic blade on the battery on either side. If it's glued, put the isopropyl alcohol under the duct tape and wait 1-2 minutes. Don't pull it by force - you can tear the plume!
What to do if the battery is too tight?
Step 3: Installation of a new battery
1. Check the new battery with a multimeter: the voltage should be 3.7-3.9V. If less than 3.5V, charge it with an external device before installation.
2 Remove the remnants of old glue from the body with alcohol and a napkin.
3. glue the new battery to double-sided scotch (includes) or use the original adhesive (e.g., B7000).
4. Connect the battery plume to the motherboard. Make sure the connector sits tight, which can cause the battery to overheat.
Step 4: Assembly of the phone
1. Connect all the plumes in reverse order. Make sure they're not skewed.
2.Turn all screws (do not pull!).
3. Set the back cover, starting at the top, press it around the perimeter for a secure fixation.
4 Turn on the phone and check the charge. If the phone doesn't turn on, double check the connection of the plumes.
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The most common mistake when replacing the battery with a Redmi 4X is to damage the display plume when the cover is separated, so if the screen does not work after assembly or colored stripes appear, then the plume has departed or broken, in which case it will need to be replaced.
Calibration of the new battery: why it matters
Once the battery is replaced, it needs to be calibrated so that the charge controller can correctly determine the level of charge, and skipping this step can lead to incorrect percentage indications or rapid loss of capacity.
Calibration instructions:
- Discharge your phone before automatically turning it off (don’t turn it back on!).
- Connect to the charger (preferably the original 5V/2A) and charge up to 100% without interruption.
- After you're fully charged, disconnect your phone and turn it on. If the light is below 100%, add it to its maximum.
- Repeat the discharge / charge cycle 2-3 times.
It is also recommended to reset calibration data through the engineering menu:
- Enter the code ##4636##.
- Select Battery Information.
- Click Reset Battery Statistics (if there is such a item).
After calibration, the new battery will hold a charge 10-15% longer, and the charge indicator will become more accurate.
Frequent Mistakes and How to Avoid Them
Even with a careful battery replacement, you can make mistakes that will lead to new problems, and here are the most common ones and ways to prevent them:
- 🔌 Flawed connection of the battery plume → Solution: Check the connector, buckle the contacts if you need it.
- 🔥 Overheating of new battery → Solution: return the battery to the seller and check the motherboard.
- 📵 Lack of network after assembly → The solution is probably not connected to the antenna plume (under the motherboard.
- 🔋 Fast discharge of the new battery → No calibration done or background processes loading the system. Solution: calibrate the battery and check the autoload of the applications.
If after the replacement, the phone began to restart or turn off at 50% charge, the problem may lie in:
- Faulty power controller on the motherboard.
- Damaged charging connector (check for oxidation).
- Incompatible battery (even if it is "suitable" in terms of parameters).
⚠️ Warning: If the phone doesn't turn on at all after the battery is replaced (even when charging), don't try to "resuscitate" it with multiple button presses. NVRAM (non-volatile memory, and will require firmware through EDL-Mode (it is better to contact the service).
How long will the new battery last?
The battery life depends on several factors:
| Factor. | Resource impact | How to prolong life |
|---|---|---|
| Battery quality | Cheap analogues lose 30% of capacity in 6 months | Buy batteries with a warranty (e.g. ZMI) |
| Charging mode | Continuous charging reduces the resource to 100% | Keep the charge in the range of 20-80% |
| Temperature. | Overheating above 40°C destroys battery chemistry | Do not play games on charging, avoid direct sunlight |
| Charging cycles | After 500 cycles, capacity drops by 20% | Use slow charging (5V/1A) |
If properly operated, a quality battery will last 2-3 years without noticeable degradation. To track its condition, install applications like AccuBattery or GSam Battery Monitor.
If you notice that the new battery starts to run out faster after 6-12 months, check:
- 📱 Background processes (c Settings) → Battery: See which apps consume the most).
- 🔌 Charger – Unoriginal power supplies can spoil the battery.
- 📶 Network signal – weak signal causes phone to spend more energy searching for network.