Xiaomi Redmi 4X is one of the most popular budget smartphones of 2017, which is still actively used due to its reliability and balanced characteristics. However, over time, even the best equipment requires maintenance, and most often the problems begin with the battery. If your Redmi 4X is quickly discharged, turned off in the cold or suddenly shut down at 20-30% charge, it’s time to deal with the battery.
In this article, we will take a detailed look at what battery is installed in the Xiaomi Redmi 4X manufacturer, how to check its condition without special devices, what analogues can be used to replace and how to correctly install a new battery.
This material will be useful for both beginners and experienced users – we have gathered all the relevant information, including technical details that are rarely mentioned in standard instructions, for example, why not all 4100 mAh batteries are the same, how to “rock” a new battery and what to do if the smartphone does not turn on after replacing.
Technical specifications of the original battery Redmi 4X
The factory battery Xiaomi Redmi 4X has the following parameters:
- 🔋 Capacity: 4100 mAh (milliamp-hours) is a key indicator that determines battery life. It is important to understand that the actual capacity may differ by the amount of energy used. ±5% of the original batteries.
- 🔌 Type: Li-Polymer (lithium-polymer) - safer and more compact compared to lithium-ion batteries of the old sample.
- ⚡ Nominal voltage: 3.85 V (typical value for modern smartphones).
- 📏 Size: approximately 150 × 70 × 3.5 mm (exact dimensions may vary slightly depending on the lot).
- 🔄 Number of charging cycles: ~500 full cycles (after that, the capacity is reduced to 80% of the original cycle).
The original battery is labeled BM47 or BM48 (depending on the batch) and is manufactured by Sunwoda or ATL — these brands are official suppliers for Xiaomi. It is important to note that the box of the smartphone is indicated capacity of 4100 mAh, but in reality, due to the characteristics of the power controller available to the user about 3900-4000 mAh.
Interesting fact: in some regions (for example, in India) sold Redmi 4X with a battery of 3500 mAh. This is due to local regulatory requirements, but in Russia and Europe supplied only the version with 4100 mAh. Check the exact model can be in the settings of the smartphone along the way Settings → About phone → version MIUI (there will be specified modification of the device).
How to check the status of the battery without disassembling the smartphone
Before deciding to replace a battery, it is worth assessing its current state. There are several diagnostic methods that do not require special tools:
- Visual signs of wear and tear: 🔋 Smartphone discharges in 2-3 hours with moderate use (social networks, instant messengers). ❄️ Turns off in the cold or at a temperature below +5°C. 📉 The percentage of charge "jumps" (for example, from 40% immediately to 15%). 🔌 Does not keep the charge off (discharged overnight).
Checking through the Engineering Menu
Type the code ##4636## in the phone app, then go to Battery Information. Notice Battery Health. If it's below 70%, change the battery.
Specialized annexes
Install the AccuBattery utility (available on Google Play) that shows the actual battery capacity, the number of charging cycles and the wear rate; normal wear up to 20% per year; if the app is 40 percent or higher, the battery is critically worn out.
Importantly, if a smartphone suddenly turns off at 20 to 30 percent charge, it's not always the battery's fault. Sometimes the problem lies in the power controller, which is the charge management chip, and then replacing the battery won't help, you'll need to repair the motherboard.
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If your smartphone is running out quickly after the MIUI update, try resetting to factory settings (Settings → Additional → Restore and Reset). Often the problem lies in optimizing the new firmware version.
When to Replace Your Battery: 5 Critical Symptoms
Some signs indicate that the Redmi 4X battery is out of order and needs to be replaced soon, and ignoring these symptoms can lead to more serious problems, including fire (although this is unlikely for lithium polymer batteries).
⚠️ Warning: If the battery is swollen (the body of the smartphone has become convex, the screen "steps away" from the frame), immediately disconnect the device and do not use it until the battery is replaced.
Top.-5 Signs that the battery is time to change:
- 🔥 Overheating when charging: if the case of the smartphone becomes hot (more than 45)°C) during charging, this is a sign of degradation of the battery's chemical elements.
- ⚡ Charging is snatched, and the percentage of charge rises and falls when you connect to the grid, which indicates that the controller is unstable or that the battery cells are damaged.
- 📵 Spontaneous reboots: The smartphone turns off and on for no apparent reason, especially when under intense load (games, video calls).
- 🕒 Charging takes more than 4 hours: if previously the battery was charged in 2-2.5 hours, and now the process is stretched by 4 hours+ This is a sign of increased internal resistance.
- 🔋 Capacity below 60%: According to AccuBattery or engineering menu, the real capacity has dropped to 2500 mAh and below.
If you see at least 2-3 items on this list, a battery replacement is inevitable. You should not delay the procedure: a worn-out battery not only spoils the user experience, but can also damage other components of the smartphone (for example, a charging connector or a motherboard due to unstable voltage).
What battery to choose for replacement: original vs analogues
When choosing a new battery for the Redmi 4X, users have two main options: the original battery from Xiaomi or a quality analog. Each of them has its pros and cons. Let's take a look at them in detail.
| Criteria | Original battery | Quality analogue |
|---|---|---|
| 🔋 Capacity | 4100 mAh (guaranteed) | 4000-4200 mAh (may be overestimated) |
| ⚡ Compatibility | 100% (no problems with the power controller) | 90–95% (probable calibration problems) |
| 💰 Price. | 1200-1800 rubles. | 500-1000 rubles. |
| 🛡️ Guarantee | 6-12 months (at official sellers) | 3-6 months (or absent) |
| 🔄 Term of service | 400-500 cycles | 300-400 cycles |
Where to buy the original battery:
- 🛒 Xiaomi’s official store (mi.com) is the most reliable option, but the price may be higher than the market.
- 🌍 AliExpress (sellers with a rating) 98%+) — Look for batteries labeled Original BM47/BM48 and reviews in Russian.
- 🏬 Local service centers – often sell original parts at wholesale prices.
If you decide to choose an analog, pay attention to the following brands:
- 🔋 ZMI (Xiaomi subsidiary – the best price/quality ratio.
- 🔌 Baseus – reliable batteries with good protection against overheating.
- 📱 Remax is a budget option, but requires a check before buying (many fakes).
⚠️ Warning: Avoid batteries with a capacity of more than 4200 mAh is a marketing hoax. The actual capacity of such batteries rarely exceeds 3800-4000 mAh, and the increased load on the power controller can lead to its failure.
Step-by-step instructions for replacing the battery with your own hands
Replacing the battery in the Redmi 4X is a moderately complex procedure that requires care and special tools. If you've never disassembled a smartphone, you'd better go to a service center, but you can do it yourself if you want, by following our instructions.
You'll need:
- ⚒️ Plastic blades (mediator) for disassembly.
- 🔧 Cross screwdriver (size) PH00).
- 🔥 Hair dryer or thermo-air station (for softening glue).
- 🧴 Isopropyl alcohol (for cleaning contacts).
- 🔋 New battery with adhesive base.
Turn off your smartphone and remove it. SIM-map|Heat the back cover with a hair dryer (temperature 60–70)°C)|Tap the lid with a plastic spatula, starting at the bottom corner|Unscrew 10 screws on the motherboard|Disconnect the battery plume first.-->
Step 1: Disassembly of the hull
Heat the back cover with a hair dryer for 2-3 minutes to soften the glue. Carefully tuck it in with a plastic blade, starting at the lower corner (near the charging connector). Be careful: under the lid there are plumes of antennas that can be accidentally damaged.
Step 2: Shutting off the battery
Once the lid is removed, unscrew the 10 screws that hold the motherboard's metal plate. First, unplug the battery plume (located at the top of the board, next to the camera). Use the plastic blade to gently lift the connector.
Step 3: Remove the old battery
The battery in the Redmi 4X is glued to the body. To remove it, pull on special "ears" (black tapes on the sides of the battery). If they are missing, tuck the battery with a plastic card, pre-drip isopropyl alcohol under it to dissolve the glue. Do not use metal tools - risk puncture of the battery!
Step 4: Installation of a new battery
Before you install the new battery, clean the contacts on the motherboard with alcohol. Stick the new battery to make sure it lies flat, without skewing. Plug the plume and assemble the smartphone in reverse order.
What if the smartphone does not turn on after replacement?
How to properly "swing" a new battery for maximum service life
Many users believe that new batteries need to be "rocked" - completely discharged and charged several times in a row. In fact, for modern Li-Polymer batteries, this is not only useless, but also harmful.
- First Charging: After installing the new battery, charge it up to 100% with the original charger (5V/2A).Do not use fast charging or wireless charging in the first 3 cycles.
- Controller calibration: Perform 2-3 full charge/discharge cycles (0% to 100%) so that the power controller correctly determines the capacity of the new battery, which will help avoid a “jumping” percentage of charge.
- Optimal charge level: Try to keep the charge in the range of 20-80%. Constant charging to 100% and discharging to 0% accelerates the degradation of lithium polymer cells.
- Avoid overheating (above 40°C) and hypothermia (below 0°C).Do not leave your smartphone in the sun or near heat sources (for example, on a car torpedo in summer).
Modern batteries do not have a memory effect, so you do not need to completely discharge them before charging. However, if you notice that the smartphone began to discharge quickly after replacing the battery, do the calibration:
- Charge your phone to 100% and hold on charging for another 1 hour.
- Turn off charging and use your smartphone until it is completely discharged (until it turns off).
- Charge to 100% without interruption.
- Repeat the procedure 2-3 times.
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Using the original charger increases battery life by 20 to 30 percent, and cheap AliExpress charging often fails to meet standard current and voltage parameters, leading to accelerated battery degradation.
Frequent battery replacement errors and how to avoid them
Even experienced users sometimes make battery replacement mistakes that can cause a smartphone to fail, and here are the most common ones and ways to prevent them:
- 🔌 Using a non-original plume: Poor quality plumes can have poor contact, leading to unstable battery performance.Buy plumes only from trusted vendors.
- 🔥 Overheating when soldering: If you solder the contacts of the battery (which is highly discouraged), do not overheat them - this can damage the power controller.°C.
- 📱 Incorrect battery installation: The battery should lie flat, without skewing. If it is set curve, it can cause damage to the plume or short circuit.
- 🔋 Using a battery with a different capacity: Installing a battery with a capacity of more than 4200 mAh can overload the power controller and its failure.
- 🔧 Loss of screws during assembly: In Redmi 4X 10 screws of varying lengths are used, and if you lose at least one, it can cause poor contact or damage to the motherboard.
If the battery doesn't turn on after the battery is replaced, don't panic, and 90% of the time, the problem is solved in the following ways:
- Check if the battery is properly connected.
- Make sure the battery fits tightly to the contacts.
- Connect the original charger and wait 10-15 minutes.
- Press the power button for 20-30 seconds (reset the power controller).
If nothing works, it's possible that the plume or the power controller was damaged during the disassembly, in which case you should contact the service center.