Xiaomi Redmi 9C is a budget smartphone with good hardware, but many users face the problem of slow charging. Even with the original 10W charger, the process can be stretched for 3+ hours. The reason lies in the software limitations of MIUI, which by default turn off accelerated charging to save battery life. In this article, we will discuss all working ways to activate fast charging, from official settings to engineering menus.
It's important to understand that the Redmi 9C physically supports charging up to 18W, but the manufacturer artificially limits it to 10W in standard mode, and this is done to extend battery life, but with the right approach, you can safely unlock extra watts. We tested all methods on MIUI 12.5-14 firmware, and we're ready to share the results.
1. Checking the current charging speed
Before you start the accelerated mode, make sure that the problem is the software constraints, not the hardware.
- 🔌 Connect your smartphone to the original charger (preferably from Xiaomi on the phone) 18W+).
- 📱 Open the Security app → Battery. → State of charge.
- 📊 Pay attention to the schedule: if the power does not exceed 5–7W, This means that energy saving policy has been activated.
An alternative way is to use the AccuBattery app (available on Google Play), which shows the exact real-time charging speed and battery temperature, and if the power doesn't go above 10W at 20 percent, your smartphone is running in limited mode.
⚠️ Note: If you use a non-original cable or power supply, the system automatically reduces the power to 5W It's a protection against overheating and battery damage.
2.Official method: MIUI settings
Xiaomi has hidden the fast charging option in the back of the menu, but it can be activated without root permissions.
- Open the settings → Battery and performance.
- Slip on the battery settings → Charging mode.
- Select the Fast Charging option (if not, go to the next section).
- Activate the switch and confirm the action.
Once activated, restart the device. In 60% of cases, this method works on MIUI 13+ firmware. If the option is missing, then your version of the software does not support it, and you will need to use alternative methods.
Check out the MIUI version (update to 13+)
Use the original 18W+ power supply
Clear the cache of the Settings application
Reboot your smartphone-->
3. Engineering menu: hidden charging settings
If the standard method didn't work, try activating fast charging through the engineering menu, which requires caution but doesn't violate warranty.
Instructions:
- Open the phone app and enter the combination: ##4636##
- In the menu that opens, select Battery Information.
- Scroll down to Fast Charge Config (could be called USB PD Config).
- Set the value of Enabled or 1.
- Save the changes and restart the device.
After you restart, check the charging speed through AccuBattery. If the power has increased to 12-15W, the method worked. If not, move to the next section.
⚠️ Note: Not all versions of the engineering menu contain the Fast Charge Config option. Some firmware may call it different or not at all. Do not change other options in this menu - this can lead to unstable operation of the smartphone.
Original 10W charger
18W+ power supply from another device
Power Bank
Wireless charging
In other ways.-->
4.Use of ADB-commands without root)
For advanced users, there is a method of activating fast charging via ADB (Android Debug Bridge) that does not require superuser rights, but requires a computer.
Step-by-step:
- Download and install Google’s Platform Tools.
- Turn on your smartphone to debug by USB (Settings → About Phone → MIUI version – tap 7 times, then go back to Additional settings → For developers).
- Get Redmi on board. 9C To PC and type in the command line: adb shell settings put global fast_charge 1
- Reset the device.
This command compulsorily triggers system-level fast charging. If the speed hasn't changed since the reboot, try an alternative command:
adb shell
settings put global usb_charging_enabled 1💡
Before using ADB, back up your data. In rare cases, incorrect commands can cause a system to crash.
5. Charging optimization: what else can be done
Even after fast charging is activated, the speed may remain unstable. Here are 5 additional tips to maximize efficiency:
- 🔥 Use a quality cable with Quick Charge 3.0 support (such as the original from Xiaomi or the Anker certified cable.
- ❄️ Charge your smartphone at a temperature of 15-30°C. When overheating, the system automatically reduces power.
- 📵 Turn off Wi-Fi, Bluetooth and background apps. They consume power and slow down charging.
- 🔄 If the battery is worn out (capacity) <80%), fast charging may not work. Check battery status in Settings → Battery. → Status.
- 🔋 Activate Air Mode while charging - this will speed up the process by 10-15%.
| Factor. | Effect on charging speed | Recommendation |
|---|---|---|
| Battery temperature | At >35°C, power drops by 50% | Remove the case, charge in the shade |
| USB cable | Cheap cables limit current to 1A | Use the original or certified |
| Background processes | Each active application reduces speed by 2-5% | Close all programs before charging |
| Battery wear and tear | At <80% capacity, fast charging may not work | Check the battery status in MIUI |
Frequent problems and their solutions
Even after the quick charging is successfully activated, users are faced with common errors.
- ⚡ Charging is jerky (fast, then slow) Cause: unstable power from the unit or overheating. Solution: use a power supply with Quick Charge and charge in a cool place.
- 🔋 After updating MIUI The reason is: reset after the update. Solution: Repeat activation through the engineering menu or ADB.
- 📉 Power is not greater than 10W Despite all the manipulations, the reason: hardware limitations on some Redmi revisions 9C (Solution: check the labeling on the box, if you're told 10W max, you can't physically squeeze it anymore.
Critical information: In some Redmi 9C batches (produced in 2021), the charging controller is hardware limited to 10W. This is evident from the marking on the board - if you have a BQ25601D chip, you can't overclock charging. Check this through the CPU-Z application (Battery section).
How to check the charging controller?
7. Alternative methods (for experienced users)
If none of these methods worked, radical measures remain, requiring root rights or an unlocked bootloader, which voids the warranty.
- 🛠️ File editing battery_charging.conf Through Root Explorer, find the file along the way. /system/etc/battery_charging.conf And change the parameter. fast_charge=0 on fast_charge=1.
- 🔧 Custom core installation Some cores (e.g. FrancoKernel) allow you to unlock additional charging modes. Requires an unlocked bootloader.
- 🔄 Modified firmware MIUI Xiaomi.eu or LineageOS firmware versions often lift charging restrictions.
⚠️ Attention: Any manipulation of system files or firmware can lead to a device blink. Before experimenting, create a full backup through the device. TWRP Make sure you have access to the Fastboot for recovery.
💡
Without root rights, the safest way to do this is through the Engineering Menu or ADB. All other methods are potentially dangerous to system stability.