Fast charging on Xiaomi Mi 9T Pro: how to turn on and speed up charging to 27 watts

Xiaomi Mi 9T Pro is the flagship smartphone of 2019, equipped with support for Quick Charge 4+ technology with up to 27 watts. However, many users are faced with the fact that the device charges slowly, despite the original charger. The reason often lies in the software limitations of MIUI or incorrect settings. In this article, we will discuss how to force fast charging, check the compatibility of accessories and avoid the typical errors that slow down the process.

It’s important to understand that the Mi 9T Pro supports three charging modes – standard (5V/2A), accelerated (9V/2A) and maximum (27V/1.2A) – switching between them automatically, but sometimes the system forgets to activate fast mode, and we will show you how to fix this without root rights and risk to the battery.

1. Check support for fast charging on the Mi 9T Pro

Before you set up charging, make sure your device and accessories are up to the requirements. Xiaomi Mi 9T Pro officially supports Quick Charge 4+, but there are nuances:

• 🔌 Charger: shall give out 5V/3A, 9V/2A or 11V/2.5A (original block from Mi 9T Pro — 27 Watt).
• 🔋 Cable: only USB Type-C with support USB 2.0 High-Speed or higher (cheap cables limit current).
• 📱 Version. MIUI: firmware MIUI 12 may not have charging optimization options.

To check the current charging mode:

1. Connect your smartphone to the charger.
2. Open the Settings. → Battery.
3. Click on the icon. ⚡ Next to the percentage of charge, the inscription “Fast Charging” will appear (if active).

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If the words “Fast Charging” don’t appear, try reconnecting the cable or using a different USB connector in the charger (some units have two ports with different power).

If instead of fast charging you see Charging (standard), the problem may be:

• 🔌 Non-original charger (even if it is 18-30 watts).
• 🔋 Damaged cable (check for bends or meltings).
• 📵 Battery Savings on (disables accelerated charging).

2. MIUI setup for maximum charging speed

MIUI hides some of the options that affect charging, so you can activate them:

1. Go to Settings → Battery → Battery settings.
2. Turn off the optimised charging option (it limits current to 80% to extend battery life).
3. Activate Quick Charging (if option is available).

If the Fast Charging option is not on the menu, use the hidden engineering mode:

1. Open the Phone app.
2. Enter the combination: ##4636###.
3. Go to Battery Information and check the AC powered bar – if USB is the value, charging is in standard mode.

Use the original 27W RAM |

Turn off battery saving mode |

Check the cable for damage |

Update MIUI to the latest version|

Reset your battery settings (if you have had problems before)

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Critical detail: on some versions of MIUI, fast charging automatically turns off at a battery temperature above 40 ° C or below 10 ° C. If the smartphone overheats, let it cool for 10-15 minutes before connecting to the network.

Selection of charger and cable

The original power supply from the Mi 9T Pro produces 27W (9V/3A), but alternative options with support for Quick Charge 3.0/4+ or USB Power Delivery (PD) are also suitable.

The cable is just as important. You need USB Type-C to charge fast.

• 🔗 Support USB 2.0 High-Speed (or higher).
• 🔧 At least 24 people lived thick. AWG (thin cables warm and limit current).
• 🛡️ Certification USB-IF (The logo should be on the packaging).

Xiaomi 27W| Review

Quick Charge 3.0 (18W)|

USB Power Delivery (PD)|

Standard 5W|

Other (write in the comments)-->

⚠️ Attention: cheap cables without protection can damage the smartphone's power controller. 9T Pro heats up in the Type-C port area, immediately turn it off and replace the cable.

4. Program restrictions and their circumvention

MIUI sometimes artificially limits the charging speed due to:

• 🔋 Battery Saving Mode (disables fast charging).
• 📱 Background processes (if the smartphone is actively used during charging).
• 🔄 Unstable connection (frequent cable connections/offs).

To eliminate the limitations:

1. Turn off Battery Saving Mode in Settings → Battery.
2. Close all background apps (especially games and navigators).
3. Activate Air Mode during charging (reduces heating).
4. Update MIUI to the latest version (in old power control bug firmware).

If after all the manipulations fast charging does not turn on, try resetting the battery settings:

1. Go to Settings → Applications → Application Management.
2. Press three points (⋮) → Resetting application settings.
3. Confirm the action and restart the smartphone.

Temperature control and safety

Xiaomi Mi 9T Pro automatically reduces the charging speed when:

• 🌡️ Battery temperature above 40°C (risk of degradation).
• ❄️ Temperature below 10°C (lithium-ion batteries are poorly charged in the cold).
• 🔥 Overheating of the processor (for example, after games).

To avoid overheating:

• 📵 Do not use your smartphone while charging (especially for games or videos).
• 🧊 Remove the cover (improves heat sink).
• 🌬️ Charge in a ventilated room (not in the sun or under a blanket).

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The optimal temperature for fast charging is 20-30°C. When you go beyond these limits, the speed drops by 30-50%.

⚠️ Attention: if Mi 9T Pro during charging heats up to 45°C and above, that's a sign:

• Faulty charger or cable.
• Damaged battery (diagnosis required).
• Type-C contaminated port (dust or contact oxidation)

6. Alternative methods of accelerating charging

If the standard methods don’t help, try:

• 🔧 Calibrate the battery: Discharge the smartphone to 0% and turn it off. Charge to 100% without interruption (preferably original RAM). Repeat the cycle 2-3 times.

Use Developer Modes

1. Activate Developer Mode (7 times click on the MIUI version in Settings → About Phone).
2. Go to Settings → Additional → For developers.
3. Turn off the limitation of background processes.

Modern lithium-ion batteries are designed for 500-800 cycles of fast charging without critical wear.