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

Xiaomi 9T (also known as Redmi K20 in some regions) is one of the brand’s most popular smartphones, but many users still don’t use its full potential, including fast charging, which can cut battery recharge time by almost half. However, by default, this option is often disabled or not working at top speed. Why is this happening?

The fact is that the manufacturer limits the charging power to extend the battery life – the standard 18W mode is turned on out of the box, but the smartphone supports higher values (up to 27W when using the original adapter). In addition, some firmware (especially custom ones) can reset or block the function due to compatibility errors. In this article, we will discuss all official and alternative ways to activate fast charging, and also tell you how to avoid typical problems.

1. Check support for fast charging on Xiaomi 9T

Before you try to turn on the feature, make sure your Xiaomi 9T supports it at all. Not all smartphone modifications are equipped with the necessary hardware.

• 🔍 Smartphone model: Fast charging is only available for versions with a Snapdragon 730 processor (codenamed davinci). 9T Pro (it has a different chipset and charging options).
• 📋 Firmware: Minimum version MIUI — 12.0.3 (earlier builds may not support the function). → The phone. → Version. MIUI.
• ⚡ Power adapter: The original unit from Xiaomi should have a marking MDY-11-EP (27 W) or MDY-08-EP (18W) Counterfeit or adapters from other devices may not start fast.

If your smartphone meets all the criteria, but fast charging still doesn't work, the problem may lie in the software settings.

2. Enable fast charging via MIUI settings

The easiest way to activate the function is through the standard smartphone menu.

1. Open Settings and go to Battery and Performance.
2. Select Charging (in some versions of MIUI it may be called Charging Settings).
3. Find the option “Fast Charge” (or Quick Charge) and move the slider to the position on.
4. Confirm the action if the system requests permission.

Once activated, connect your smartphone to the original adapter, and the lock screen should show the words “Fast Charging” or “Turbo charging” on the lock screen, if not, check the cable (it should support USB Type-C 2.0 or higher) or try another connector.

Original adapter Xiaomi (27 W) connected | Used proprietary cable Type-C| MIUI version not lower than 12.0.3| Option "Fast Charging" is included in the settings-->

⚠️ Warning: If after the function is turned on, the smartphone begins to overheat (temperature above 45)°C), immediately turn off fast charging and check the battery for wear. Prolonged overheating can cause the battery to bloat and damage to the motherboard.

3. Alternative methods of activating fast charging

If the standard method didn't work, try one of these options, and they'll be suitable for users with custom firmware or unofficial MIUI builds.

Method 1: Engineering menu (for advanced users)

This method requires caution, as incorrect actions can disrupt the operation of the smartphone.

1. Open the Phone app and enter the combination: ##4636##.
2. In the menu that opens, select Battery Information.
3. Find the Fast Charge string and click on it. If the option is inactive, try changing the value from false to true.

If the engineering menu isn't available, it might be blocked by the manufacturer, and then the only thing that helps is flashing it.

Method 2: Use of the ADB-team

For this method, you will need a computer with ADB drivers installed and USB debugging enabled on your smartphone.

adb shell settings put global fast_charge 1

Once you have the command, restart the device. If the fast charging doesn't work, check if the settings have reset after the reboot (this happens on some custom firmware).

4.Compatible accessories for maximum charging speed

Even if you have enabled fast charging in the settings, its actual speed depends on the accessories used. Xiaomi 9T supports several standards:

• ⚡ Quick Charge 4+ (Up to 27 watts – requires an original adapter MDY-11-EP.
• ⚡ Quick Charge 3.0 (up to 18 watts) – works with most certified adapters.
• ⚡ USB-PD (Up to 18W – compatible with MacBook or Google Pixel charging.

Here is a table with recommended accessories and their characteristics:

Note that cheap, uncertified cables can not only reduce charging speeds, but also damage the smartphone's power controller. Always check for a USB-IF certificate on the package.

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If you travel frequently, take the original Xiaomi adapter with you. Charging at hotels or airports rarely supports Quick Charge 4+, and your Xiaomi 9T will charge 2 to 3 times slower.

Typical problems and their solutions

Even when set up correctly, fast charging can be unstable, and here are the most common situations and ways to fix them:

Problem 1: The word “Fast Charging” appears, but the speed is low

Reasons:

• 🔌 Uses a non-original cable (for example, from an old smartphone with a Micro-USB).
• 📉 Battery worn out (capacity below 80% of nominal value).
• 🔥 The smartphone overheats and the system automatically reduces power.

Solution: Replace the cable with a certified USB Type-C, check battery status through the AccuBattery app, and let the device cool before charging.

Problem 2: Fast charging shuts down after 10-15 minutes

This is due to the MIUI defense mechanism, which restricts current at high temperatures, to get around the constraint:

1. Charge your smartphone in a cool room (optimally - 20-25 ° C).
2. Remove the cover (it can hold heat).
3. Turn on Airplane Mode to reduce the processor load.

⚠️ Warning: If the smartphone turns off when connected to charging (especially at a battery level below 15%), this is a sign of critical battery wear!

6.How to check the actual charging speed

To make sure that fast charging actually works, use one of these apps:

• 📊 AccuBattery – shows current, voltage and temperature in real time.
• 🔋 Ampere – displays current current strength (for Xiaomi) 9T in fast mode it should be at least 2.5-3.5 A).
• 📈 Battery Guru – analyzes the charging speed and compares it with reference values.

For the test:

1. Discharge the smartphone to 5-10%.
2. Connect the original adapter and start the application.
3. Check the charging time to 50%. When working properly, the Xiaomi 9T should gain 50% in 30-40 minutes.

If the indicators are much worse, check:

• 🔌 Cable and adapter for damage.
• 📱 Type-C port for dust or oxidation (clean with alcohol).
• 🔄 Try another outlet (possibly the problem is network voltage).

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The optimal charging speed for the Xiaomi 9T is 15 watts or higher. If the app shows less than 10 watts, the fast mode is not activated.

7.Myths and truths about fast charging on Xiaomi 9T

There's a lot of rumors going around this feature, and we're going to look at the most popular ones.

Myth 1: Fast charging will ruin the battery in six months

❌ Modern lithium polymer batteries are designed for 500-800 cycles of charging, regardless of speed.°C) really shortens the lifespan.Solution: charge your smartphone in a cool place and don't use it while charging for games or videos.

Myth 2: You can use any high-power adapter.

❌ Dangerous! Adapters without Quick Charge support can deliver unstable voltages that damage the power controller. Always check compatibility.

Myth 3: Fast charging only works with the original cable

✅ True, but with reservations, the cable must support a current of at least 3 A and be certified. USB-IF. For example, cables from Anker or Belkin often work as well as the original ones.

FAQ: Frequent questions about fast charging Xiaomi 9T