You plugged Xiaomi into a charger, and 10 minutes later, the body became hot like an iron? That's not always a cause for panic - modern smartphones with support for fast charging (for example, the Redmi Note 12 Pro).+ s 120W or POCO F5 s 67W) It can be heated to 40-45°C in the process of recharge, but if the temperature is above 50°C, and the phone starts to brake or spontaneously turn off, this is an alarm, and in this article we will discuss why this happens, when the heating is normal, and when it requires intervention, and what to do to avoid damage to the battery.
First, it’s important to understand that any smartphone warms up when charging — it’s a physical process of converting electricity into heat. POCO) There are features that can increase heating: aggressive fast charging algorithms, budget materials for enclosures in entry-level models (for example, Redmi). 10A), And there's also a common problem with substandard third-party components.
1.Fast charging: why Xiaomi is warming up more than others
Fast Charging Technology (33W, 67W, 120W Xiaomi allows you to charge your battery 100 percent in 20 to 40 minutes, but you have to pay for that speed with heat. The simple way of working is that the higher the power (watts), the more energy passes through the power controller and the battery per unit of time — which means more heat is released. For example, Xiaomi 13 Ultra with 90W-The charger can be heated to 42-47°C, which is considered the norm for flagships.
But there are nuances:
- 🔋 Budget models (Redmi) 9A, POCO M4 Pros often do not have an effective cooling system (no graphite pads or copper tubes), so they warm more than flagships.
- ⚡ Adaptive charging in new firmware MIUI 14+ Automatically reduces power when overheating, but not all users update the software.
- 📉 Battery wear: After 300-500 charging cycles, battery capacity drops and internal resistance rises, leading to additional heating.
How do you check if the temperature is above critical values? Use applications like AIDA64 or CPU Monitor if the battery sensor is above 50°C when charging is a reason to sound the alarm. For comparison: the normal values for different Xiaomi models are shown in the table below.
| Model phone | Max. Charging power. | Normal temperature during charging | Critical temperature |
|---|---|---|---|
| Redmi Note 12 Pro+ 5G | 120W | 40–48°C | >55°C |
| POCO F5 Pro | 67W | 38–45°C | >52°C |
| Xiaomi 13 Lite | 67W | 35–43°C | >50°C |
| Redmi 10C | 18W | 30–38°C | >45°C |
⚠️ Warning: If the phone is heated to 50°C and above in the first 5 minutes of charging, immediately disconnect it from the mains.This may indicate a short circuit in the battery or a malfunction of the power controller.
2. Non-original chargers: the main cause of overheating
Around 60% Xiaomi’s overheating problems when charging are due to the use of substandard or uncertified adapters and cables, because Xiaomi’s original chargers have built-in chips that regulate voltage and current depending on the battery temperature. The side of the "nouneim"-charges often give stable 5V/2A or 9V/2A without any adaptation, which leads to:
- 🔥 Overloading of the power controller (especially dangerous for models with MediaTek Helio chips, for example, Redmi) 9T).
- 📉 Accelerated battery degradation (capacity loss of 20-30% in 6 months).
- ⚡ Risk of fire due to lack of protection from short circuit.
How do you check the originality of the charger?
- 🏷️ Labeling: Original Xiaomi adapters have laser engravings of logo and model (e.g, MDY-12-ED for 120W-charging).
- 🔌 Weight and dimensions: counterfeits are usually lighter and smaller in size.
- 💡 LED: the originals it burns with an even white light, the copies often flashes or has a bluish tint.
If you are already using non-original charging, but want to minimize the risks, follow this checklist:
Use a Certificate Cable USB-IF (The logo should be on the packaging)
Do not charge your phone during games or videos
Turn off charging when you reach 80-90%
Avoid charging in the heat (above 30)°C indoors)-->
⚠️ Warning: Never use a charger with a power higher than that of your phone, for example, if your Redmi Note 11 is designed to be powered by a battery. 33W, And you do. 67W-adapter, the power controller will work at the limit, which will lead to overheating.
3. Background processes and "heavy" applications
Many users are unaware that charging your phone when you use it actively (games, video editing, streaming) increases heat by 2-3 times. POCO X5 Pro with simultaneous charging can raise the temperature to 50-55°C. Why this is happening?
The fact is that the processor (Snapdragon or MediaTek) and the graphics accelerator (Adreno/Mali) under load consumption to 70% If you're charging at this point, it's the battery:
- The battery receives current from the adapter and at the same time gives it to power the chips.
- The power controller is operating in overload mode, trying to balance the flow of energy.
- The heat from the processor and battery is added up as they are located close together.
The most “gluttonous” applications that increase heating when charging:
- 🎮 Games: PUBG Mobile, Call of Duty, Genshin Impact (load on the phone) GPU 90%).
- 🎥 Video Editors: CapCut, KineMaster, Adobe Premiere Rush.
- 📱 Social networks with autoplay video: TikTok, Instagram Reels.
- 🗺️ Navigators: Google Maps, Yandex.Navigator (constant work) GPS mobile).
How do you reduce the heat?
- 🛑 Close all background apps before charging (use Settings) → Annexes → Launched).
- ⚙️ Enable the Power Saving Mode (Settings) → Battery → Energy saving regime).
- 🔄 Turn off auto-update apps on Google Play.
💡
If you need to charge your phone and use your navigator, turn on the flight mode while you're charging. GPS, reduce heat by 15-20%.
4.Battery problems: when it's time to change the battery
The average battery life of Xiaomi smartphones is 2-3 years (or 500-800 charge cycles), after which the capacity drops by 20-40%, and internal resistance increases, which leads to:
- ⚡ Increased heating even with slow charging (5W–10W).
- 📉 Fast discharge (for example, from 100% to 1% in 4-5 hours without loading).
- 🔋 Battery bloating (phone body starts to "spark", the screen can move away from the frame).
How to check the status of the battery?
- Open the Settings. → Battery → Battery status (available on MIUI 12+).
- Use the AccuBattery app (showing real capacity and wear in %).
- Look at the time: If the phone runs out in 2-3 hours in normal use, the battery is worn out.
Critical signs for which you need to immediately replace the battery:
| Symptoms. | Reason. | Risk |
|---|---|---|
| The phone turns off at 20-30% charge | Unstable stress due to cell degradation | Data loss, sudden shutdown |
| The body is swelling, the screen is moving. | Gas formation inside the battery | Battery rupture, fire. |
| Charging is jerky (1%, then 10%) | Controller or contacts damaged | Short circuit. |
The cost of replacing the battery in Xiaomi service centers:
- Redmi 9/10 series: 1 500–2 500 ₽.
- POCO X3/X4: 2 000–3 000 ₽.
- Xiaomi 11/12/13 series: 3 500–5 000 ₽ (due to the complexity of disassembly).
⚠️ Warning: Never try to replace the battery yourself if you have no experience with the battery. BMS-A faulty connection may cause the motherboard to fire or break down.
5. Software failures and MIUI errors
Sometimes the cause of overheating are bugs in the firmware, especially after updates. MIUI. In 2023, Redmi Note 11 Pro users will be able to+ Massively complained of heating up to 50°C when charging after updating to MIUI 14.0.4. It was the fault of:
- 🐛 Errors in the Linux kernel responsible for power management.
- 🔄 Miui.analytics service, which constantly sends data in the background.
- 📱 Conflicts with the shell HyperOS (new firmware for global models).
How to diagnose a software problem?
- Check the error log through Developer Options (included in Settings) → The phone. → Version. MIUI — tap 7 times).
- Use the team in ADB: adb shell dumpsys batterystats (details energy consumption statistics).
- Reverse to the previous version MIUI Recovery Mode (instruction below).
Solutions:
- 🔄 Reset the settings to factory (Settings) → Additionally. → Resetting settings).
- 📥 Flash your phone through the Mi Flash Tool (instructions on the official Xiaomi website).
- 🚫 Disable unnecessary services: Settings → Annexes → Application management → Systemic → miui.analytics (disable)
How to get back to the previous version of MIUI?
External factors: heat, humidity, mechanical damage
Even a good Xiaomi phone will warm up when charging if:
- 🌡️ Ambient temperature above 35°C (for example, if you charge your phone in the sun or in your car in the summer).
- 💦 Humidity above 80% (condensation inside the housing can cause short circuits).
- 📱 The phone lies on a soft surface (pillow, blanket), which blocks the vents.
- 🔌 Connector. USB-C contaminated or deformed (dust, contact oxidation increase resistance).
How to minimize the impact of external factors?
- 🌬️ Charge your phone in a cool, dry place (optimum: 20-25).°C).
- 🧴 Use silica gel (shoe box bags) if you live in a humid climate.
- 🔍 Clean the connector regularly USB-C Wooden toothpick (not metal objects!).
- 🚫 Do not use your phone while charging if it is on a soft surface.
💡
Optimal conditions for charging Xiaomi: temperature 20-25°C, humidity up to 60%, clean connector USB-C and the original charger.
7. Hardware malfunctions: when repairs are needed
If you've ruled out all of the above, but Xiaomi's phone still warms up when charging, the problem may be a hardware breakdown.
| Breakdown | Symptoms | Cost of repair |
|---|---|---|
| Faulty Power Controller (PMIC) | The phone does not turn on, charging is jerky, strong heating in the upper part | 2 000–4 000 ₽ |
| Short circuit on the motherboard | Phone turns off when charging, smell of burning | 3 000–8 000 ₽ |
| Damaged USB-C connector | Charging is only in one position of the cable, heating the bottom of the phone. | 1 000–2 500 ₽ |
| Tap. BGA-chips (processor, memory) | The phone brakes, spontaneously reboots, warms up even without charging. | 4 000–10 000 ₽ |
How to diagnose a hardware problem?
- Try charging your phone from a different adapter and cable.
- Check if the phone is warming without a SIM card and memory card (sometimes the problem is in the slot contacts).
- Connect your phone to your PC and check charging logs via Mi PC Suite.
⚠️ Warning: If the phone smells like a burn or there are dark spots on the case (especially near the connector). USB-C), Take it to the service center immediately, and these are signs of internal components burning.