Why does the Redmi phone heat up when charging: is it normal or a dangerous signal?

You connected Redmi Note 12 or Redmi 10C to charging, and after 10 minutes the case became hot, like a cup of tea? Do not rush to panic - in 80% of cases this is a normal phenomenon associated with the physics of lithium-ion batteries. But what if the heating is accompanied by slow charging, spontaneous reboots, or a burning smell? Then we are talking about potentially dangerous malfunctions that require immediate action.

In this article we will analyze all possible causes of overheating smartphones Xiaomi Redmi when charging - from harmless (for example, using a powerful adapter) to critical (blowing battery). You will learn how to distinguish normal heating from emergency heating, what measures to take on your own, and when to run to a service center. At the end - checklist for diagnostics and answers to frequently asked questions from owners Redmi 9A, Note 11 Pro and other popular models.

Spoiler: if your phone heats up to 40–45°C during fast charging and cools down 15-20 minutes after disconnecting the cable - this the norm for most modern smartphones with support Fast Charging. But there are 3 signs at which you need to sound the alarm: the temperature is higher 50°C, corrosion on the connector or sudden charging shutdown. Details are below.

1. Physics of the process: why does any phone heat up when charging

Heating up a smartphone while charging is not a bug, but physical property of lithium-ion batteries. When current passes through the battery, chemical reactions occur that inevitably generate heat. The higher the current (measured in amperes), the more intense the heating. For example: A), the more intense the heating. For example:

• 🔋 Standard charging (5W, 1A): heating up to 30–35°C is barely noticeable.
• ⚡ Fast charging (33W, 3A): heating up to 40–45°C —the body is warm, but does not burn.
• 🔥 Ultra-fast charging (120W, 6A): heating up to 50°C+ —requires active cooling.

Models Redmi with support Fast Charging (for example, Redmi Note 12 Pro+ s 120W) heat up more due to the high current density. The manufacturer includes this in the design: inside the case there are heat pipes and graphite spacers for heat dissipation. But if you use non-original cable or adapter, the cooling system may not cope.

Key point: normal heating should be uniform. If only the lower part of the case (where the connector USB-C) or one corner heats up, this is a sign of a local problem (for example, contact oxidation). You should also be wary if the phone gets hot after 1-2 minutes after connecting to the network, this may indicate a short circuit in the power circuit.

2. TOP 5 reasons for overheating Redmi when charging (and how to eliminate them)

If your Redmi heats up more than usual, check these factors in order - from simple to complex.

🔌 Reason 1: Non-original or damaged cable/adapter

Cheap cables with AliExpress or counterfeits Xiaomi often have thin cores that cannot withstand high currents. This leads to:

• 🔥 Local heating in the connector area USB-C.
• ⚡ Slow charging (the phone shows “Charging”, but the percentage does not increase).
• ⚠️ Automatic shutdown charging after 5–10 minutes.

Solution:

1. Check the cable for kinks, melts or exposed wires.
2. Use only certified adapters with support Quick Charge or Power Delivery (for models Redmi with fast charging).
3. Clean the connector USB-C from dust and debris with a toothpick (carefully!).

📱 Reason 2: Background processes and “heavy” applications

If while charging you:

• 🎮 Playing Genshin Impact or Call of Duty Mobile.
• 📹 You edit the video in CapCut.
• 🔄 You update the system or applications via Play Market.

... then the processor (Snapdragon or Mediatek) and the graphics accelerator work at the limit, which increases heating. In this case, the temperature may reach 50–55°C, and charging will be slower than usual.

Solution:

• Close all applications before charging (double tap the "Home" button → swipe up).
• Activate mode Energy saving in settings (Settings → Battery).
• Turn off automatic application updates in Play Market.

🔋 Reason 3: Wear or damage battery

Lithium-ion batteries degrade over time. After 300–500 cycles charging, their capacity decreases and internal resistance increases - this leads to:

• ⏳ Longer charging (for example, Redmi 9T it takes 3-4 hours to charge, not 2).
• 🌡️ Increased heating (even with standard charging 10W).
• 📉 Sudden shutdowns during 20–30% charge.

Check the battery status:

1. Enter the code in the phone application:

   ##4636##

2. Go to the section Battery information.
3. Compare indicator Health level (Battery Health) with the norm:

Battery condition	Health level (%)	Recommendations
Excellent	90–100%	No action required.
Satisfactory	70–89%	Monitor heating, avoid fast charging.
Critical	Less than 70%	Replace the battery at a service center.

Warning! If the battery swelled (the phone body has become convex, the screen “moves away” from the frame) — immediately unplug the phone from charging and do not use it. Risk of fire!

🦠 Reason 4: Viruses or malware

Some viruses (for example, mining or spyware) load the processor to 100%, which leads to overheating even without charging. Signs of infection:

• 📈 Unexplained traffic consumption (check in Settings → SIM cards and mobile networks).
• 🔋 Rapid battery drain in standby mode.
• 🚫 The appearance of unfamiliar applications in the menu.

Solution:

1. Install an antivirus (Dr.Web or Kaspersky) and scan the system.
2. Check the list of installed applications (Settings → Applications).
3. Reset the phone to factory settings (Settings → Advanced → Recovery and reset).

🔧 Reason 5: Faulty power controller

The charging controller (a microcircuit on the motherboard) regulates the current flowing into the battery. If it is damaged, the phone can:

• 🔥 Get warm even when the screen is off.
• ⚡ Charge in jerks (sometimes quickly, sometimes slowly).
• 💥 Turns off when connected to charging.

This malfunction cannot be fixed on your own - it requires diagnosis at the service center. center replacement of the microcircuit. Average repair cost: 1 500–3 000 ₽ (depending on the model).

3. How to check the temperature Redmi without a thermometer

You can evaluate the phone's heating in three ways:

📱 Method 1: Built-in tools MIUI

1. Open Settings → Battery.
2. Tap on the energy consumption graph.
3. The current battery temperature (for example, 38°C).

🔍 Method 2: Hidden engineering menu

Enter the code in the phone application:

##4636##

Go to section Battery information (Battery Information). The following are displayed here:

• 🌡️ Temperature (Temperature).
• 🔋 Charge level (Level).
• ⚡ Voltage (Voltage).

📊 Method 3: Third-party applications

Install one of these apps from Play Market:

• AIDA64 - shows the temperature of the processor, battery and other components.
• CPU Monitor - monitors heating in real time with graphs.
• AccuBattery - analyzes battery health and charging speed.

Normal temperature indicators for Redmi when charging:

• 🟢 30–40°C —optimal mode.
• 🟡 40–45°C —permissible for fast charging.
• 🔴 45°C+ —risk of battery damage.

4. What to do if Redmi gets warm when charging: step-by-step guide

Follow this algorithm to eliminate overheating:

1. Step 1. Disconnect the phone from charging and let it cool until 30–35°C (check through the engineering menu).
2. Step 2. Check the cable and adapter:
   • Use only original accessories Xiaomi.
   • Inspect the connector USB-C on the phone to see if there is any debris or oxidation there.
3. Step 3. Close all applications and disable background processes:
   • Swipe up from the bottom edge of the screen and close all application cards.
   • Disable Wi-Fi, Bluetooth and mobile data (if not are using).

Step 4. Activate power saving mode:

• Go to Settings → Battery → Power saving mode.
• Select option Balanced or Super energy saving.
• Step 5. Check the battery status via the engineering menu (code ##4636##).
• Step 6. If all else fails — perform a reset to factory settings (Settings → Advanced → Recovery and reset).

Attention! If after all the manipulations the phone continues to heat up 50°C+, don’t take risks - contact the service center. Possible problems:

• Swelling or leakage of electrolyte in the battery.
• Short circuit on the motherboard.
• Power controller malfunction.

5. How to prevent overheating Redmi when charging: 7 preventive measures

To ensure your Redmi does not turn into a “heating pad” every time you charge, follow these recommendations:

1. Use original accessories:
   • The power adapter must support the technology Quick Charge (for models with fast charging).
   • The cable USB-C must be certified (USB-IF).
2. Do not charge the phone in a case:
   • Thick silicone or leather cases impair heat transfer.
   • Remove the case if the temperature exceeds 40°C.
3. Avoid extreme temperatures:
   • Do not leave the phone in the sun or near heaters.
   • Do not charge in temperatures below 0°C or above 35°C.
4. Do not play games during charging:
   • Startup PUBG Mobile or Genshin Impact increases the heating of the processor.
   • If you need to charge urgently, activate the mode Game without recharging in MIUI.
5. Update the firmware:
   • The manufacturer regularly releases patches to optimize energy consumption.
   • Check for updates in Settings → About phone → System update.
6. Calibrate the battery:
   • Once every 2-3 months, discharge the phone to 0% and charge until 100% without interruptions.
   • This helps reset charging controller errors.

Use wireless charging with caution:

• Wireless chargers get hotter than wired ones.
• Do not place your phone on soft surfaces (sofa, bed) for charging - this will block ventilation.

Myths about charging that you shouldn’t believe

1. “You should always discharge your phone to 0% before charging” - this was true for nickel batteries 20 years ago. Modern lithium-ion batteries, on the contrary, “do not like” deep discharges.

2. “Charging at night ruins the battery” - there is protection: after MIUI there is protection: after 100% the phone is disconnected from the power supply and is recharged only when it drops to 95%.

3. “Fast charging kills the battery in a year” - if used correctly (do not heat the phone, do not charge in a case), even 120Wcharging will not reduce the service life by more than 10–15%.

6. When overheating Redmi is a reason for repair

There are 5 signals when self-medication is dangerous and you need to take the phone to the service:

1. The phone turns off when connected to charging:
   • Cause: short circuit in the power circuit or a malfunction controller.
   • Risk: failure of the motherboard.
2. Battery is swollen:
   • Signs: the phone body has become convex, the screen “moves away” from the frame.
   • Risk: fire or explosion of the battery.
3. Charging occurs jerkily or does not occur at all:
   • Cause: oxidation of contacts on the battery or motherboard.
   • Risk: complete loss of phone functionality.
4. The phone heats up even when turned off:
   • Cause: hardware malfunction (for example, breakdown of a transistor).
   • Risk: damage to other components.

There is a burning smell or smoke:

• Cause: overheating or fire of internal components.
• Risk: irreversible damage to the phone.

Average cost of repair in service centers (2026):

Type of repair	Cost (₽)	Term (days)
Replacement battery	1 200–2 500	1
Connector repair USB-C	1 500–2 000	1–2
Replacing the power controller	2 000–3 500	2–3
Diagnostics of the motherboard	500–1 000	1

Attention! If you notice at least one one of the listed symptoms, do not try to repair the phone yourself. Incorrect intervention (for example, an attempt to open the case without tools) can lead to:

• Loss of warranty (if the phone is new).
• Damage to cables or microcircuits.
• Increasing the cost of repairs.

7. Frequently asked questions about overheating Redmi when charging

❓ Why Redmi Note 11 heats more than the old one Redmi 7A?

Redmi Note 11 supports fast charging 33Wwhereas Redmi 7A is charging on 10W. The higher the charging power, the more intense the heating. This is normal if the temperature does not exceed 45°C.

❓ Is it possible to use the phone while charging if it is heating up?

It is possible, but with reservations:

• 🟢 Allowed: calls, instant messengers, watching videos.
• 🔴 It is prohibited: games, video editing, system updating.

If the temperature exceeds 45°C, it is better to interrupt use.

❓ Why the phone heats up even when charging from Power Bank?

Reasons:

1. Power Bank poor quality (does not hold the declared power).
2. You are using a cable that does not support fast charging.
3. The battery Power Bank is worn out (swollen or lost capacity).

Solution: try another Power Bank (for example, Xiaomi Mi Power Bank 3) and the original cable.

❓ How long should it heat up Redmi during fast charging?

Normal indicators:

• 30–40°C —light heating, barely noticeable.
• 40–45°C - warm body, but does not burn.
• 45°C+ - critical heating, you need to turn off charging.

Models with 120W-charging (Redmi Note 12 Pro+) can heat up to 50°C in the first 10–15 minutes, then the temperature stabilizes.

❓ What to do if the phone gets hot and does not charge?

Action algorithm:

1. Try a different cable and adapter.
2. Clean the connector USB-C from debris.
3. Reboot the phone into Safe Mode (hold the power button → "Reboot in Safe Mode").
4. If that doesn't help, take it to a service center (it may be faulty power controller).

If your problem is not solved, describe it in the comments, indicating the phone model, charging type and symptoms. We will try to help!