How to enable fast charging on Xiaomi Mi 9T: all the ways and nuances

Xiaomi Mi 9T

18W

In this article, we’ll take a look at all the working ways to enable fast charging on the Mi 9T, from basic settings to hidden engineering menu features. You’ll learn which chargers are really supported, how to check the current charging speed, and what to do if a smartphone ignores fast charging, despite having a compatible adapter.

It is important to understand that fast charging on Xiaomi Mi 9T is not always activated automatically, due to battery optimization, firmware or even cable malfunction, we tested all methods on different versions of MIUI (including global and Chinese) and collected only working solutions.

If you’re tired of waiting for your phone to charge up to 100% in 3+ hours, this guide will help you reduce the time to 1 hour 20 minutes (when using the original Xiaomi 18W charger).

1. Checking the compatibility of the charger

Before digging into the settings, make sure your charger does support fast charging for the Mi 9T. The smartphone is equipped with Quick Charge 3.0 technology, but only works with certain adapters.

The original charger from the Xiaomi Mi 9T kit has 18W power (9V/2A or 5V/3A).If you use a third-party adapter, check its specs:

• 🔌 Supported protocols: Quick Charge 3.0/2.0 or Power Delivery (PD)
• 📊 Power: not less 18W (optimally — 9V/2A)
• 🔗 Cable: must support data transmission (normal charging cables often limit speeds)

How to check the current charging speed?

1. Connect your smartphone to the charger.
2. Open the Security app → Battery.
3. Click on the icon. ⚡ in the upper right corner - the current power will be displayed (for example, 18W or 10W).

⚠️ Attention: If power is lower 15W, This means that fast charging is not activated, and this may be due to an incompatible adapter, a damaged cable, or a disabled function in the settings.

If you are using a non-original charger, try connecting the original or proven from the Anker, Baseus, Ugreen brands with Quick Charge 3.0 support.

2. Enable fast charging via MIUI settings

In some versions of MIUI, the fast charging function is disabled by default to extend the battery life.

Step 1. Open Settings → Battery and performance.

Step 2. Go to Battery Settings (or Additional Settings, depending on the firmware version).

Step 3. Find the option:

• 🔋 Fast charging (in global firmware)
• 🔌 Enable fast charging or optimized charging (in Chinese firmware)

If you don't have that option, your version of MIUI doesn't support manual activation, so move on to the next method.

Some firmware has the option hidden to find it.

1. Enter the search for settings (Settings → Search) the request "Fast charging".
2. If you don’t have any results, try the English version: “fast charging”.

⚠️ Attention: On firmware MIUI 12.5+ The fast charging option can automatically shut down at high battery temperature (above 40)°Check the temperature in the Battery section → Status.

3. Activation through the engineering menu (for advanced)

If standard settings don't work, you can turn on fast charging via the engineering menu, which works on most versions of MIUI, but you need to be careful.

Step 1. Open the Phone app and enter the combination:

##4636##

Step 2. In the menu that opens, select Battery Information.

Step 3. Check the current charging status:

• 🔋 AC Powered – Connected to the network
• ⚡ Charging (fast) – fast charging is active
• ⏳ Charging (slow) – standard charging

If the status is slow, go to Battery Settings (if available) and enable the Fast charge option.

The following is the case (for MIUI 11-12):

1. Install the MTK Engineering Mode app from Google Play.
2. Go to Hardware Testing → Charging.
3. Enable the Fast Charging option (if available).

Once activated, restart your smartphone and check the charging speed through the Battery or Ampere app (available on Google Play).

4.Problems and Solutions: Why Fast Charging Doesn't Work

Even after turning on all the settings, the Mi 9T can ignore fast charging, and let’s look at the main reasons and ways to fix them:

If none of the methods worked, the problem may be:

• 🔋 Battery wear (check status in Settings) → Battery. → Status).
• 🔌 Damaged port. USB-C (Try to clean the port with compressed air).
• 📱 Software failure (reset settings via Settings) → Resetting settings).

💡

If fast charging is unstable, try calibrating the battery: completely discharge the phone before turning off, then charge to 100% without interruptions. Repeat the procedure 2-3 times.

5. Optimal conditions for fast charging

To make Xiaomi Mi 9T charge as fast as possible, follow the following conditions:

• 🌡️ Battery temperature: 15-35°C (when overheating, the speed automatically decreases).
• 📵 Flight mode: Turn it on to reduce the load on the processor.
• 🔄 Closed Applications: Complete all background processes through Recent Apps → Close it all down.
• 🔋 Charge level: fast charging works more efficiently 10-80%.

Also avoid:

• ❌ Using your phone while charging (especially games or videos).
• ❌ Connecting to the computer through USB (power-limited 2.5W).
• ❌ Charges in the case (may cause overheating).

To monitor the charging speed in real time, we recommend the Ampere app, which shows current (in mA) and voltage, which helps to assess the efficiency of the charger.

💡

Using the original Xiaomi 18W charger + cable from the kit guarantees maximum charging speed. Third-party adapters can run slower even at the declared power.

6. Alternative methods of accelerating charging

If standard fast charging doesn’t suit you, consider these options:

1. Wireless charging (Mi 9T requires an adapter)

Charging via Power Delivery (PD)

• 🔌 Adapters with PD (For example, from MacBook or Google Pixel can give up to 27W, but require a compatible cable.
• ⚠️ Risk of battery overheating during prolonged use.

3. Custom firmware (for experienced users)

• 📱 Firmware like LineageOS or Pixel Experience can unlock additional charging modes.
• ⚠️ Installation of custom firmware voids the warranty and can lead to unstable operation.

Before experimenting with alternative methods, check:

1. Compatible with Mi 9T (via Ampere app)
2. Battery temperature (must not exceed 40°C).
3. Battery status (if capacity has dropped below 80%, fast charging may be limited to the system).

FAQ: Frequent questions about fast charging on Xiaomi Mi 9T