Why is this happening with Redmi 8?
Owners of Xiaomi Redmi 8 often face the problem of spontaneously turning off the smartphone – the device goes out without warning, sometimes even with a charge above 50%. Unlike Xiaomi flagship models, where this behavior is usually associated with battery wear, in Redmi 8 the root of the problem lies in the combination of budget hardware and features of MIUI firmware.
This model came out in 2019 with a Snapdragon 439 processor and a 5000 mAh battery, but after 2-3 years of operation, many users notice that the phone begins to “die” by 30-40% of the charge or completely shut down when loaded. What is the matter – a hardware defect, a software error or a consequence of improper charging?
Important: If your Redmi 8 only turns off at low temperatures (below +5°C), it's normal for lithium-ion batteries to temporarily drop their capacity. But if the shutdowns happen under normal conditions, read on.
1. Battery wear is the main cause of sudden shutdowns
The Redmi 8 battery is designed to last 500 to 800 charge cycles, then its capacity is reduced by 20 to 30 percent, and the power controller (the chip that displays percentages of charge) does not always correctly track the actual state of the battery, so the phone shows, for example, 30 percent, and in fact the charge is already at zero - and the device turns off.
How to check the wear of the battery:
- 📱 Install the AccuBattery app (free on Google Play) and check the Health setting (battery health). If it's below 80%, the battery needs to be replaced.
- 🔋 Enter the number ##4636##, go to Battery Information and compare Charge Level (should be close to Battery status.
- 🔌 Connect charging and observe: If the phone only turns on 5-10 minutes after the cable is connected, the battery is dead».
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If the Redmi 8 turns off when it's under 15%, but it's 0% after the reboot, which is a sure sign that the battery controller is lying. Try calibrating the battery: completely discharge the phone, then charge to 100% without interruption.
The cost of replacing the battery in the service center is from 1,500 to 2,500 rubles (2026).If you decide to change your own, choose a battery with the brand BM47 or DM47 - these are the original analogues from Xiaomi.
2. firmware failures and MIUI errors
Redmi 8 ran MIUI 10-12 out of the box, but many users upgraded to the latest versions, and that's where the problems started. The fact is that the new firmware is optimized for modern processors, and the Snapdragon 439 with its 4 Cortex-A53 cores does not always cope with the load, the result: the phone overheats and turns off for protection.
Typical symptoms of program failures:
- 🔄 The phone only turns off when you start certain applications (such as games or cameras).
- 📵 Before turning off the screen flashes or a message appears MIUI stopped.
- 🔥 Phone hot to the touch (especially in the processor area).
Decisions:
- Reset the settings to factory: Settings → About phone → Reset settings.
- Reverse to the stable version of MIUI via Fastboot (instruction below).
- Install custom firmware (e.g. Pixel Experience) if you are ready to lose the warranty.
How to get back to the old version of MIUI?
3. Processor overheating and trottling
The Snapdragon 439 in Redmi 8 is warmer than the processors in the newer Xiaomi models. At temperatures above 60°C, the protection is triggered - the phone is forced to turn off.
- 🎮 During games (PUBG Mobile, Genshin Impact).
- 📸 With long-term video shooting in 1080p.
- ☀️ In hot weather (above) +30°C) or when charging.
How to check the temperature:
- Install the AIDA64 application.
- Open the Sensors section and see the CPU value.
- If the temperature exceeds 55 ° C in plain – cleaning or replacement of the thermal paste is required.
Decisions:
- 🧹 Clean the charging and speaker connector from dust (use a soft brush or compressed air balloon).
- 🛠️ Replace the heat paste (in the service it is worth it) ~800 rubles).
- 📉 Limit productivity: in Settings → Battery. → Select the Performance Mode for Energy Saving.
Games.|Charging.|Photo/video|In hot weather.|Friendly.-->
4. Maternity board malfunctions
If the phone turns off even with a new battery and fresh firmware, the problem may lie in the power circuit on the motherboard.
- 🔌 Oxidation or tipping of contacts PMIC (power-controller).
- 🔥 Burning elements in the charging circuit (often after using non-original RAMs).
- 📡 Damage to the antenna module (may cause short circuit).
Diagnosis:
| Symptoms. | Probable cause | Decision |
|---|---|---|
| The phone is powered on only from charging, but does not hold the charge. | BQ25601D (responsible for charging) is defective | Chip replacement (~2,000 rubles) |
| Turns off when vibrating or impacting | Microcracks on the board or the dumping of elements | Rate of contacts (~1 500 rubles). |
| Does not respond to the power button, but vibrates when connected to the RAM | Problems with PMIC or EDL firmware | Flashing in EDL mode or replacing the chip |
⚠️ Warning: If the phone turns off with a characteristic click or burn smell, immediately take it to the service.
5. Power button problems
The mechanical on/off button in Redmi 8 wears out or sticks over time. If the button contacts oxidize or the spring weakens, the phone can spontaneously turn off when pressed or vibrated.
How to check:
- 🔘 Press the power button 10-15 times in a row, and if it fails or creaks, you need to change it.
- 🛠️ Disassemble the phone (if you have experience) and check if the button plume is moving away from the board.
- 🔧 Try to turn on the phone without a button: connect the charger and hold Volume up + Loudness down for 10 seconds.
The cost of replacing the button in the service is 500-1 200 rubles. If you decide to change yourself, buy a button with a metal mount (plastic analogues quickly break).
Check the reaction to the press (click, backlash)
Connect charging – the phone should turn on without a button
Try to turn on via fastboot (keep Volume down + Power)
Check the button for oxidation (when disassembling)-->
6.The impact of third-party applications and viruses
Some applications (especially SEOs, antiviruses, or aggressive ad games) can conflict with MIUI and cause critical errors that cause shutdowns, and viruses like Adware or Trojan can overload the processor, leading to overheating and emergency shutdowns.
How to find the culprit:
- Run your phone in Safe Mode (hold the power button → Safe Mode). If there are no shutdowns, the problem is with third-party software.
- Check the list of recently installed applications: Settings → Applications → Application Management.
- Install Malwarebytes and scan the system for viruses.
Top.-5 Applications that cause crashes on Redmi 8:
- 🚫 Clean Master (optimizer, conflict with the MIUI).
- 🚫 UC Browser (contains hidden miners).
- 🚫 ES Conductor (Old Software with Vulnerabilities).
- 🚫 Likee (social network with aggressive background consumption).
- 🚫 Cheat games (can damage system files).
⚠️ Note: If the phone only turns off when connected to Wi-Fi or mobile network, check your settings VPN Some operators (e.g. Tele2) block traffic, which can cause disruptions to the network. MIUI.
7.Problems with charger and cable
Non-original chargers (especially those with >2A output current) can damage the Redmi 8 power controller. Also, a worn cable with damaged insulation can cause short circuits that cause the phone to turn off.
Signs of problems with charging:
- ⚡ The phone is only turned off while charging.
- 🔌 The swelling is then turned off (and then turned off).
- 🔥 The cable or adapter is warmer than usual.
Decisions:
- 🔌 Use only the original Xiaomi RAM (5V/2A) Certified analogues (Baseus, Anker).
- 🔍 Check the connector. USB-C On the phone: if it is wobbling, a replacement is required.
- 📊 Turn on the percentage charge level display: Settings → Battery. → Charge percentage – this will help to track the moments of a sharp drop.
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Never use laptop (19V) or quick charge (Quick Charge 3.0+) charges for Redmi 8 – this will speed up battery wear and can damage the power controller.