You're used to your Xiaomi Redmi Note charging from 0 to 50% in 30 minutes, but suddenly noticed: the indicator shows Charging, and the percentages crawl like a snail? Or the phone even writes "Slow Charging", although you use the original power supply? The problem with fast charging is one of the most common complaints of owners of Xiaomi smartphones, especially after 1-2 years of operation. 80% of cases are not to blame for iron breakdowns, but banal user errors or software failures.
In this article, we’ll look at all the possible reasons why the Redmi Note (any model from the Note 8 Pro to the Note 12) might “refuse” fast charging, and give you step-by-step instructions on how to diagnose and troubleshoot a problem. You’ll learn how to check the cable, power supply, USB port, and even hidden system settings that can block high speeds.
1.A damaged cable or power supply is the first cause of slow charging
To start with, 9 out of 10 fast-charging problems are connected to a cable or an adapter, and even if they look whole, the inner veins could have been rubbed, oxidized, or burned out, especially for cheap, nouneime cables that come with powerbanks or are sold on Aliexpress for 50 rubles.
How to check:
- 🔌 Try another cable and power supply, best of all the original from Xiaomi (labeling) MDY-11-ED or MDY-12-EU If fast charging is working, the problem is accessories.
- 🔍 Look at the cable on the curves. Most often, the sections on the connectors are rubbed (USB-A, USB-C) Pull the plug, and if the wires are playing, it means the veins are torn.
- 📱 Check the power supply with a multimeter (if any). 5V/3A, 9V/2A or 10V/2.25A (If the voltage is lower, the adapter is faulty.
⚠️ Warning: Never use power supplies from other devices (such as a laptop or tablet) unless they support Quick Charge. 3.0/4.0 or MI Fast Charge.This can not only slow down charging, but also damage the battery.
2.Contaminated or damaged USB-C port
The USB-C port on the Redmi Note is one of the most vulnerable places: Dust, pile from the pocket, moisture or mechanical damage (for example, after a fall) can disrupt contact, causing the phone to “not see” the supported fast charging protocol and goes into 5V/1A (slow charging) mode.
Signs of a problem:
- 📵 The phone charges quickly or slowly (depending on the position of the cable).
- 🔌 When you connect the cable, you get a notification saying, Charging suspended. Humidity in the port».
- 🔍 Foreign particles or bent contacts are visible in the port.
How to clean the port:
- Turn off the phone and get it out. SIM-memory-card.
- Take a wooden toothpick (not metal!) and carefully remove dust from the port. You can use compressed air (a canister to clean the equipment).
- If the contacts are oxidized (green coating), wipe them with an alcohol solution (90%+).
- Allow the port to dry for 10-15 minutes before connecting the cable.
What to do if the contacts are bent?
⚠️ Warning: Do not use cotton swabs to clean the port - the villi can stay inside and aggravate the problem. Also avoid metal objects (needles, paper clips) so as not to close contacts.
3. firmware failures or disabled fast charging in settings
Sometimes fast charging is turned off not because of hardware problems, but because of software failures, which can happen after a MIUI update, reset settings or install custom firmware, and some users accidentally turn off the feature in the battery menu without even knowing it.
How to check the settings:
- Go to Settings → Battery and Performance → Battery Settings
- Find the Quick Charge (or MI Fast Charge) and make sure the switch is active.
- If you don’t have an option, your Redmi Note model doesn’t support fast charging (for example, the Redmi Note 7 charges at a maximum of 18W, and the Note 10 Pro charges at 33W).
Resetting battery settings:
If fast charging is on but not working, try resetting your battery settings:
Settings → Applications → Application Management → Three Points (menu) → Resetting Application Settings → Select “Battery”After resetting, restart your phone and check the charging.
💡
If the quick charging is gone after the MIUI update, try rolling back to the previous firmware version via Settings → About Phone → System Update → Three Points → Select an update pack.
4. Battery wear and tear - why charging slows down over time
The lithium polymer batteries in Xiaomi smartphones are designed for 500-800 charging cycles. After that, their capacity decreases, and the battery controller begins to limit the charging current to extend the battery life. If your Redmi Note is older than 2 years, chances are that the problem is precisely wear and tear.
How to check the status of the battery:
- 📊 Install the AccuBattery app (available on Google Play) and it will show the actual battery capacity and the number of charging cycles.
- 🔋 B Settings → Battery and productivity → Check the battery status (if this option is available on your model).
- 🔌 If the phone charges to 100% in 1-1.5 hours, but discharges in 3-4 hours in normal use, the battery is worn out.
The critical wear of the battery occurs when the capacity falls below 70% of the nominal, for example, if the battery was originally at 5000 mAh, and now shows 3200 mAh, it urgently needs to be replaced.
| Battery capacity | Status. | Recommendations |
|---|---|---|
| 90–100% | Excellent. | Keep using, keep an eye on the temperatures. |
| 80–89% | Good. | Avoid full discharge, charge up to 80-90% |
| 70–79% | Satisfactory | Prepare for a replacement within a year |
| Less than 70% | Critical | Battery replacement is required |
⚠️ Note: If you decide to replace the battery, buy only original batteries (code begins with the first battery). MBJ or MDY) Or certified analogues from Anker, Baseus. Cheap batteries from China may not support fast charging or even swell over time.
5.Overheating phone - why charging slows at high heat
Xiaomi Redmi Note automatically reduces the charging current if the battery temperature exceeds 40-45 ° C. This is protection against battery damage.
- 🔥 Genshin Impact (Call of Duty Mobile) while charging.
- ☀️ Charging in the sun or in a hot room (for example, in a car in summer).
- 📱 Use of a non-original power supply unit with insufficient cooling.
- 🚫 Closed case blocking heat sink.
How to avoid overheating:
- 🎮 Do not play games while charging (or use Battery mode) → Energy conservation).
- 🌡️ Remove the case while charging if the phone is warming.
- 🔌 Charge your phone in a cool place (not on a windowsill in the sun!).
- ❄️ If the phone is already overheated, disconnect it from charging and let it cool for 15-20 minutes.
Remove the case
Disable background applications
Move your phone to a cool place
Use the original power supply unit
Do not play games while charging-->
6. firmware problems or application conflict
Sometimes fast charging is turned off due to MIUI crashes or conflicts with installed applications (especially with “battery optimizers” or “charging accelerators” from Google Play).
Solutions:
- 🔄 Reboot your phone – sometimes it helps to reset the power controller’s temporary errors.
- 📱 Remove third-party charging management applications (e.g. Battery Guru, Fast Charging Master) that often conflict with native algorithms MIUI.
- 🔧 Reset the settings to factory (pre-make a backup!): Settings → The phone. → Resetting settings → Resetting all settings
- 🔄 Update. MIUI up to the latest version or roll back to stable firmware if the problem appears after the update.
⚠️ Note: If you have installed custom recovery (TWRP) Or LineageOS, or Pixel Experience, fast charging might not work because there are no drivers for the power controller, and you'll have to go back to the stock. MIUI.
💡
If fast charging is gone after updating MIUI, try to clear the system cache: Settings → Memory → Cleanup → Cache system.
7. Hardware malfunctions: power controller or motherboard
If you have tried all of the above, but fast charging has not worked, the problem may lie in a hardware breakdown:
- 🔌 Faulty Power Controller (Chip) PMIC) — It's responsible for the distribution of current. When it breaks, the phone can only charge on the back of the car. 5V/1A.
- 📱 Damaged walkways on the motherboard – often occurs after falling or getting moisture.
- 🔋 Bloated battery - can press on board and cause short circuits.
Signs of hardware malfunction:
- The phone does not turn on without a connected charge.
- The charge is jerky (fast, then slowly, then stops altogether).
- Artifacts appear on the screen or the phone spontaneously reboots.
In this case, self-repair is not recommended - it is better to contact the service center.The cost of diagnosis - from 500 rubles, repair of the power controller - from 2000 rubles (depending on the model Redmi Note).
💡
Before you travel to the service, back up your data via Settings → Additional → Backup and Reset, as a complete reset may be required during repairs.