Xiaomi Redmi 4X is one of the most popular budget smartphones of the brand, released in 2017. Despite its venerable age, the device is still actively used due to the balanced characteristics and the ability to install custom firmware. However, over time, many owners face the problem: the phone began to charge indecently for a long time. If the battery was filled in 1.5-2 hours, then now the process stretches for 4-5 hours or even hangs by 80-90%.
In this article, we will explore all the possible causes of slow charging Redmi 4X, from the banal wear of the cable to hidden settings of the system, you will learn how to diagnose the problem, which parameters to check first, and what to do if standard methods do not help, and pay special attention to the specifics of this model: its hardware limitations, features of firmware and typical “diseases” of the battery after 3-5 years of operation.
Importantly, not all solutions are universal. For example, resetting can help with software failures, but it will make things worse if the battery wear is to blame, so we structured the material from simple to complex, from checking the charger to diagnosing the power controller.
1. Problems with charger and cable
To start with, 60 percent of slow charging cases are due to a faulty or unoriginal charger. The Redmi 4X supports maximum charging current 2A at 5V, but if the power supply or cable fails to provide these parameters, the charging speed drops by 2-3 times.
How to check:
- 🔌 Use the original power supply from Xiaomi (marking) MDY-08-EG or MDY-08-EM). The power must be at least 10Watt (5V/2Fakes are often issued only 1A, which increases the charging time to 4+ hours.
- 📱 Try another cable. Even the original cable gets rubbed over time at the base of the Micro-USB connector, which causes you to lose contact. Especially if the phone is charging in jerks or interruptions.
- 🔋 Check the Micro-USB connector on your phone. When you connect the cable, it should sit tight, without backlash. If the connector wobbles, it's a sign of mechanical wear (replace the connector or use a magnetic adapter cable).
Quick test: connect the Redmi 4X to another charger (like a Quick Charge tablet) If the charging speed has increased, the problem is in your power supply. If not, look deeper.
⚠️ Warning: Never use chargers with an output voltage higher than 5V (e.g., from a 19V laptop) this can disable the smartphone's power controller, after which it will stop charging altogether.
Battery wear: how to check and what to do
The Redmi 4X is equipped with a 4100 mAh lithium polymer battery, and the average lifespan of these batteries is 300-500 full charge cycles (approximately 2-3 years of active use), after which the capacity drops by 30-50%, and the charging speed decreases due to:
- 🔋 Increased internal resistance of the battery (it takes the current worse).
- 📉 Failures in the charging controller, which begins to limit the current for "safety".
- ⚡ False percentage display (phone shows 100%, and after 5 minutes it turns off).
How to diagnose wear:
- Install the AccuBattery app (available on Google Play) and it will show the actual battery capacity and charging speed in mA.
- If the actual capacity is less than 2500 mAh, the battery is critically worn out and needs to be replaced.
- Pay attention to the voltage schedule: if it jumps when charging (for example, from 4.2V to 3.9V) - this is a sign of degradation of elements.
| Battery status | Real capacity. | Charging speed | Recommendations |
|---|---|---|---|
| New (0-1 year) | 3800-4100 mAh | 1500–2,000 m | Optimal condition |
| Average wear (1-2 years) | 3000-3,800 mAh | 1000-1500 m | Monitor the temperature, avoid full discharges |
| Severe wear and tear (2-3 years) | 2000-3000 mAh | 500 to 1,000 mA | Battery replacement is recommended |
| Critical wear (3+ years) | Less than 2,000 mAh | Less than 500 mA | Replacement is mandatory, sudden shutdowns are possible |
Important: Redmi 4X has a removable back cover, but the battery is soldered to the board with a plume, and the replacement is better entrusted to the service center, since if you disconnect improperly, you can damage the power controller.
3. Software failures: settings and firmware
If the hardware is fine, but the Redmi 4X is still charging slowly, the problem may be in the software.
- 🤖 Failures in the power management system (especially after updates) MIUI).
- 📱 Background processes that consume up to 30% of charging current (e.g. Google Play Services sync or viruses).
- 🔄 Incorrect charging settings (for example, the “Battery Savings” mode during charging).
What to do:
- Turn off unnecessary background processes: Go to Settings → Applications → Launched and pause energy-intensive applications (social networks, instant messengers, games). In Settings → Battery → Battery Use, check which applications consume the most power.
- Reset the battery settings: MIUI has a hidden battery reset function. Go to Settings → About Phone and tap MIUI 5 times. Then go back to Settings → Battery → Menu (three dots) → Reset statistics.
- Update or reflash your phone: Check for updates in Settings → About Phone → System Update. If your phone hasn’t been updated in a long time, consider installing custom firmware (like LineageOS), but that requires unlocking the bootloader.
Check the temperature of the phone while charging (should not be above 40°C)
Turn off Wi-Fi and mobile data while charging
Make sure the "Do Not Disturb" mode is on.
Try charging your phone in safe mode (hold the power button → Safe Mode)
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If the charging speed has not changed after these manipulations, the problem may be in the power controller or the Redmi 4X firmware.
4.Overheating phone: Hidden enemy of charging
Xiaomi Redmi 4X is built on a Qualcomm Snapdragon 435 processor, which is prone to overheating, especially when charging and loading simultaneously (games, video, navigation). At temperatures above 40 ° C, the system automatically reduces the charging current to protect the battery, as a result, the phone can charge for 5-6 hours or completely stop charging by 80%.
How to check the temperature:
- 🌡️ Install the app AIDA64 or CPU Monitor – These show the temperature of the processor and battery in real time.
- 🔥 If the battery temperature is above 45°C, and the processor is above 50°C, this is a critical value.
How to eliminate overheating:
- 📵 Do not use your phone while charging (especially for games or videos).
- ☀️ Charge in a cool place (not in the sun, not under the blanket, not in the car in the summer).
- 🧊 Remove the cover - it can block the heat sink.
- 🔄 Clean your phone of dust (especially the Micro-USB connector and speaker grille).
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If your phone is too hot even in plain, try replacing the heat paste on the processor. The Redmi 4X will suit the Arctic MX-4 or KPT-8, which will reduce the temperature by 5-10 ° C.
⚠️ Warning: If the battery temperature exceeds 50°C, immediately disconnect the phone from charging! further heating can cause the battery to bloat and even catch fire.
5. Problems with the Micro-USB connector and power controller
The Micro-USB connector in the Redmi 4X is one of the most vulnerable points, and over time, its contacts oxidize, bend, or move away from the board, leading to:
- 🔌 Unstable contact (phone is charged, then not).
- ⚡ Reduced charging current (instead of 2A goes 0.5A).
- 💥 Short circuit (in rare cases).
How to diagnose:
- Light a flashlight into the Micro-USB connector. If you see darkening, green plaque or bent contacts, the connector needs cleaning or replacement.
- Try wiggling the cable in the connector, and if the phone starts charging only in a certain position, it's a sign of poor contact.
- Check if the connector is hanging when you connect the cable. A backpack of more than 1 mm indicates mechanical wear.
Decisions:
- 🧹 Clean the connector: Turn off the phone and clean the connector gently with a toothpick or cotton swab dipped in alcohol. Don't use metal objects - they can close the contacts!
- 🔧 Replacement of the connector: The cost of replacement in the service is about 500-1000 rubles. If you are an experienced user, you can replace yourself (Micro-USB connector for Redmi). 4X worth ~200 rubles).
- 🛠️ Power Controller Check: If the problem remains after the connector is replaced, the controller may have been damaged PMIC (Diagnosis requires special equipment (multimeter) and soldering skills.
What happens if you don't repair the connector?
6.Influence of custom firmware and root rights
Redmi 4X is a popular model among fans of custom firmware (LineageOS, Pixel Experience, Havoc-OS). However, not all firmware is optimized for proper operation with the power controller, which can lead to:
- 🐢 Artificially limiting charging current (firmware developers may understate values for "safety").
- 📉 Incorrectly displaying charging percentage (e.g., the phone shows 100% but is actually charged at 80%).
- 🔋 Fast discharge due to unoptimized processor cores.
How to check:
- Install the Battery Charge Current app, which will show the actual charging current, and if it's below 500 mA on the original power supply, the firmware limits charging.
- Check the kernel settings in the Kernel Adiutor app (if there is root).
Decisions:
- 🔄 Return to the official firmware MIUI: Download the latest stable version MIUI for Redmi 4X (codename santoni from en.miui.com.Swipe through Fastboot or Recovery (instructions are available on the forum) 4PDA).
- 🛠️ Custom core: If you use custom firmware, check the settings in Device Control or EX Kernel Manager.Make sure the max charging current setting is set to 2,000mA.
Warning: If you are not sure about your skills, it is best not to experiment with firmware. Installation incorrectly can lead to a "brick" (complete failure) of the phone.
7. Alternative charging methods
If the standard methods don’t help, you can try the alternative charging options of the Redmi 4X:
- 🔌 Wireless charging: Redmi 4X It does not support Qi out of the box, but you can buy a special adapter receiver (costs) ~300 rubles. The charging speed will be lower (~500-700mA, but it's better than nothing.
- 🔋 External battery (powerbank): Use powerbank with Quick Charge support 2.0/3.0 (Xiaomi Mi Power Bank, for example 3). Make sure the cable supports high current (it is better to take the original one). USB-C To Micro-USB from Xiaomi).
- 📱 Charging from computer/laptop: Speed will be low (~300 to 500 mA, but it's fine at the very least. USB 3.0 (blue ports) – they give a little more current.
If neither method works, the last option is to replace the battery or repair the board, which will cost 1000-2000 rubles in the Xiaomi service center or at the proven masters (depending on the region).
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If the Redmi 4X only charges when it’s off, it’s a sign of a serious problem with the power controller or battery, in which case self-repair is not recommended!