How to make fast charging on Xiaomi Redmi 9T: from settings to selecting RAM

Xiaomi Redmi 9T is one of the most popular budget smartphones with a capacious battery of 6000 mAh, but standard charging power 10W often disappoints users slow speed. Many owners do not even suspect that the device supports fast charging 18W — but only under the right conditions. In this article, we will discuss how to activate accelerated charging, which chargers are suitable, and why even with the original RAM smartphone can charge slowly.

It’s important to understand that the Redmi 9T doesn’t have a built-in fast-charging controller in the chip (unlike the flagships), so the speed depends on three factors: power supply, cable and firmware. If you use a native charger from the kit (5V/2A), the maximum you get is 10W. To unlock 18W, you will need to buy additional accessories and customize your smartphone. Next is a step-by-step instruction with nuances that are not written in the official manuals.

1. Checking the current charging speed: how to find out the real power

Before you try to speed up charging, you need to understand how fast it's going now. USB-Tester – enough built-in tools MIUI or free applications.

Method 1: via a hidden engineering menu, enter the combination in the Phone app:

##4636##

Go to Battery Information. This will show the current charging current in mA (milliamps). For example, a value of 1500 mA at 5V means a power of 7.5W (5 × 1.5 = 7.5).

Method 2: Monitor apps: Install AccuBattery (available on Google Play) or Ampere, which not only shows current but also battery temperature, which is critical for safety. If you connect 18W RAM to less than 1,000 to 1,200 mA, the problem is either the cable or the firmware settings.

• 🔋 Norm for 10W: 1000-1500 m at 5V
• ⚡ Norm for 18W: 1800-2500 m at 9V
• ❄️ Dangerous mode: current above 3000 mA or battery temperature >40°C

⚠️ Note: If after the connection of the CC 18W The smartphone shows currents of 500 mA or less, which is a sign of slow activation due to overheating or battery wear.

2.What Chargers Are Suitable for Redmi 9T: Compatibility Table

The official Redmi 9T kit includes a 5V/2A (10W) power supply that doesn’t unlock the smartphone’s potential. 18W requires a Quick Charge 3.0 or Power Delivery (PD) charger to activate. However, not all RAMs are equally efficient — below is the table of proven models.

An important nuance: even with the right RAM, the Redmi 9T does not always automatically switch to 9V. Sometimes you need to force fast charging through settings (for this in the next section), also pay attention to the cable: it must support current up to 3A (complete with the Redmi 9T cable only goes to 2A).

3. Enabling fast charging in MIUI settings: hidden options

By default, MIUI can limit the charging power to save battery life. To remove this limitation, you need to:

1. Go to Settings → Battery and Performance → Battery settings
2. Activate the Fast Charging Switch (if any).
3. In some versions of the firmware, the option is hidden - then you need to turn on the developer mode:

Settings → About the phone → MIUI version (stamp 7 times)


Settings → Additional → For developers → Debug USB (enable)




Settings → Additional → For developers → Optimization of charging (disable)

After that, the smartphone should automatically recognize the RAM with support for Quick Charge and switch to 9V. If this does not happen, check:

• 🔌 Cable: Try another one (preferably labeled) 3A or QC).
• 🔄 Reboot: sometimes helps to restart a smartphone with connected RAM.
• 📱 Firmware: on older versions MIUI (12.5) may not be supported PD.

Used RAM with support for QC 3.0 or PD| Cable is designed for current ≥3A| In settings enabled mode "Fast Charging" | Smartphone rebooted after connecting a new ZU-->

⚠️ Attention: On some firmware, after switching on fast manual charging, the smartphone begins to warm up stronger than usual.°C (checked in AccuBattery), return the settings to the original state - this will protect the battery from degradation.

4.Why charging is slow even with an 18W RAM: 5 reasons

You bought a powerful charger, you turned on all the settings, but the Redmi 9T still charges like a turtle?

1. Battery wear. After 300 to 500 charging cycles, the battery capacity drops, and the controller limits the current. Check the battery status in AccuBattery. If it's below 80%, it's time to think about replacing.
2. Background: Applications that use GPS or mobile internet (like Google Maps or Telegram) can eat up charge faster than it comes in.
3. Cheap cables often have thin veins that can't withstand high current. Check the cable for damage.
4. Overheating. If your smartphone is in the sun or in a case, the system automatically reduces the power. Charge the device in a cool place.
5. MIUI Limitation: In some regions (e.g. the EU), Xiaomi software reduces the charging speed to comply with safety regulations, which is treated by changing the firmware region (but requires unlocking the bootloader).

The fifth reason is particularly insidious: For example, in the European firmware (MIUI EU), fast charging can be blocked at the kernel level. If you are sure that this is the problem, try reflashing your smartphone on MIUI Global or Xiaomi.EU (but remember the risks of losing warranty!).

5. Alternative ways to speed up charging (without buying a new RAM)

If you do not want to buy a new charger, you can try to speed up the charging of the existing RAM using software tricks:

• 🛠️ Disable Charging Optimization. Go to Settings → Battery → Settings → Optimize charging and deactivate the option. This will disable the current limit on the last 20% of the charge.
• ⚡ Turn off the mobile network and Wi-Fi — without background activity, the smartphone will charge 15-20% faster.
• 🔄 Switching USB-When you connect to the RAM in the notification curtain, tap on Charging through USB and select File Transfer (MTP). Sometimes it's a little bit restrictive. MIUI.
• 🧊 Cool. Put your smartphone on a metal surface or use a cooling stand.°C controller allows for more current.

Another non-obvious life hack: if you have a Power Bank with Quick Charge support, plug your smartphone into it instead of an outlet. Many external batteries (such as Xiaomi Mi Power Bank 3 Pro) deliver 18W more stable than network RAM.

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If your smartphone charges slowly from your computer, try connecting it to your computer. USB-port 3.0 (usually blue) – they give more current than USB 2.0.

Risks of fast charging: how not to kill the battery in six months

Accelerated charging is always a trade-off between battery speed and battery durability. Lithium polymer batteries degrade faster when:

• 🔥 High temperature (above 40)°C).
• ⚡ Constant charging at maximum current.
• 📉 Deep discharge (below 10%).

To minimize harm, follow the rules:

1. Do not use fast charging daily, optimally 1-2 times a week.
2. Turn off accelerated charging after 80% (you can set automatic shutdown in AccuBattery settings).
3. Avoid charging in the sun or in the car in the summer.
4. Once a month, perform battery calibration: discharge the smartphone to 0%, then charge to 100% without interruptions.

If you notice that the battery has started to run out in half a day (when used before), check its condition in AccuBattery. Health value below 70% is a direct signal to replace. The average life of the Redmi 9T battery in intensive use is 2-3 years.

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Fast charging reduces battery life by 10 to 15 percent per year with daily use, and the optimal balance is to alternate between regular and accelerated charging.

7. Battery replacement: when it really needs to be

If all the ways to speed up charging didn't work, the problem could be a worn-out battery.

• 📉 The smartphone discharges in 3-4 hours with normal use.
• 🔌 The swelling is then lifted, and the swelling is).
• 🔥 The body is noticeably heated even without loading.
• 🕒 Autonomous life has decreased by 2 times compared to the new state.

The cost of replacing the battery with a Redmi 9T in service centers is 1500-2500 rubles (depending on the region). You can save by buying the original battery (Xiaomi BM4B) and replacing it yourself, but this requires experience: with careless dismantling, it is easy to damage the plumes.

After replacing the battery, be sure to complete 2-3 full charge/discharge cycles to calibrate the controller. Also update the firmware to the latest version - newer versions of MIUI have improved battery support.

FAQ: Frequent questions about the Redmi 9T charging