What to Know About Fast Charging on the Redmi Note 9 Pro
Xiaomi Redmi Note 9 Pro supports fast charging technology Fast Charge 3.0 (18 watts), but many users are faced with the fact that the smartphone charges slowly — even with the original charger. the reason is often not a hardware malfunction, and incorrect settings or use of incompatible accessories.
In this article you will find:
- 🔌 Step-by-step instructions for enabling fast charging in settings MIUI.
- ⚡ List of compatible chargers and cables (including third-party brands).
- ⚠️ Common errors that cause the function to fail.
- 🔧 Methods of diagnosing battery and charging problems.
Important: The Redmi Note 9 Pro (model joyeuse) is equipped with a 5020 mAh battery, and it requires not only the right software to charge it effectively, but also a cable that supports Quick Charge 3.0/4.0 or USB Power Delivery. If you use a cheap cable from another device, fast charging may not be activated.
Step 1: Check the compatibility of the charger and cable
Before you change your smartphone settings, make sure your charger and cable support fast charging.The original kit from the Redmi Note 9 Pro includes a 33W power supply (the MDY-11-EP model), but even with it, the feature may not work if:
- 🔌 Cable damaged (peteretration of the span, bent contacts).
- ⚡ Uses a non-original adapter with a power of less than 18 watts.
- 📱 Port port USB-C on the smartphone contaminated (dust, oxidation of contacts).
How to check compatibility:
- Look at the marking on the charger: 18W (9V/2A) or higher must be indicated.
- Use a cable labeled USB 2.0 Type-C or higher (better USB 3.1).
- Connect your smartphone to charging and check the notification: if the word “Quick Charging” appears, everything is fine.
| Type of charger | Support for fast charging | Notes |
|---|---|---|
| The original Xiaomi 33W block (MDY-11-EP) | ✅ Yes (18W) | Maximum power is limited by the firmware of the smartphone. |
| Third-party blocks (Anker, Baseus, Samsung) | ✅ Yes, if you support QC 3.0) | Recommended power: 18W-30W. |
| Charges from older Redmi models (10W) | ❌ No. | Maximum speed: 10W (normal charging) |
| Wireless charging (Qi) | ❌ No. | The Redmi Note 9 Pro does not support wireless charging. |
⚠️ Note: If you use powerbank, make sure it maintains power output at least 18W. Many portable batteries are limited 10W–15W, which blocks the activation of fast charging.
Step 2: Enabling fast charging in MIUI settings
By default, the Redmi Note 9 Pro should automatically activate fast charging when you connect a compatible device, but in some firmware (especially custom ones), this feature can be disabled.
Connect an original or compatible charger
Make sure your battery is less than 80%
Close all background apps (especially games and instant messengers)
Check the temperature of the smartphone (should be below 40°C)
-->
- Open Settings → Battery and Performance.
- Select Battery Settings → Charging Mode.
- Activate the “Fast Charging” option (if available).
- Restart your smartphone (sometimes required to apply changes).
If the “Fast Charging” item is not on the menu, it may mean:
- 📱 You have an outdated version. MIUI (firmware update).
- 🔧 In the smartphone installed custom software (for example, LineageOS), where the function is disabled.
- ⚡ The charger does not support Quick Charge 3.0.
💡
If the smartphone gets too hot after fast charging, temporarily turn off the function and check the battery for wear (for example, through the AccuBattery app).
Step 3: Diagnostics of charging problems
If fast charging doesn’t work even after checking the equipment and settings, perform a diagnosis:
- Check the temperature of the smartphone: 🌡️ If the temperature is above 40°C, MIUI It will automatically turn off fast charging. Let the device cool down for 10-15 minutes and reconnect.
Ampere
- Install Ampere from Google Play.
- Connect the charging and check the current: when fast charging, it should be ≥ 2000 mA.
- Reset the battery settings: Settings → Applications → Application management → Three dots (menu) → Reset the application settings
If the problem persists after the update, try:
- 🔄 Reset the settings to factory (with data saving):
- 📱 Install custom Recovery (for example, TWRP) and run a clean version MIUI.
💡
Updating the firmware is the most effective way to fix software errors of fast charging. If after the update the problem remains, the iron (port, cable or battery) is to blame.
Step 5: Check the status of the battery and USB-C port
Over time, the battery and charging connector wear out, which can block fast charging.
1. Battery diagnostics
- 📊 Install the AccuBattery app and check: Battery capacity (if less than 4,000 mAh, a replacement is required) Charging speed (should be) ≥18W Temperature (optimum: 25-35)°C).
- 🔋 If the battery is swollen or deformed, stop using your smartphone immediately!