How to turn off fast charging on Xiaomi Mi 9: 4 proven ways

Xiaomi Mi 9 is the flagship smartphone of 2019, which is still relevant due to the powerful hardware and support for updates. However, owners of the device often face the problem of rapid wear of the battery, especially when using the fast charging function. According to research, the constant use of accelerated charging can reduce battery life by 15-20% after 1-1.5 years of intensive operation.

In this article, we’ll look at all the ways you can turn off fast charging on the Mi 9, from standard settings to hidden engineering menus, how to reduce battery load, avoid overheating, and extend the life of your device, and whether you should turn off fast charging at all, and what alternative ways to save the battery are available.

Why does fast charging hurt the Xiaomi Mi 9 battery?

The Quick Charge 4+ technology, which the Mi 9 supports, can charge up to 50% in 30 minutes, but the speed comes with accelerated battery wear.

• 🔥 Battery overheating – with fast charging, the battery temperature can rise to 40–45°C, which destroys its chemical structure.
• ⚡ High current – standard charging delivers 1-1.5A, and fast – up to 3A and higher, which increases stress for the batteries.
• 📉 Charging cycles – each full cycle (0–100%) reduces battery life.
• 🛠️ Power controller – over time, may fail, which leads to unstable charging.

According to tests from Battery University, lithium-ion batteries that are constantly charged at high currents lose up to 30% of their capacity after 300-400 cycles, compared to 500-600 cycles with gentle charging.

⚠️ If your Mi 9 starts to unplug at 20 to 30 percent charge or heat up even without load, it's a sign of critical battery wear, and then turning off fast charging won't help - you need to replace the battery.

Method 1: Disconnect via standard MIUI settings

The easiest way is to use the built-in options, and MIUI (even in older versions for the Mi 9) has a hidden charging power limiting feature, and here's how to activate it:

1. Open Settings → Battery and Performance.
2. Go to Charge (or Charging Settings depending on the MIUI version).
3. Slap the icon. ⚙️ (Additional settings) in the upper right corner.
4. Find the option to Limit Charging or Fast Charging and turn off the slider.

If you don’t have this option (which is typical of MIUI 10–11 on the Mi 9), try the alternative route:

Settings → Special features → Additional features → Limiting charging

In some firmware, the feature may be called Sparing Charging or Night Charging, and if that doesn't work, move on to the next one.

Method 2: Engineering menu (for experienced users)

If standard settings fail, you can use the Engineering Mode, a method that requires caution, as improper actions can cause malfunctions in the device.

Instructions:

1. Open the phone app and enter the combination: ##4636##
2. In the menu that opens, select Battery Information.
3. Scroll down and find the Fast Charge Config or Quick Charge string.
4. Then, tap it and select Disable.
5. Reset the device.

If #4636### doesn’t work, try the alternative code.

##6484##

⚠️ In the engineering menu, do not change other options, especially those related to Modem, RF This can cause network loss, overheating, or even a device blink.

Method 3: Disconnect via ADB (for advanced users)

If previous methods have failed, you can use Android Debug Bridge (ADB), which requires connecting your smartphone to your computer and basic command line knowledge.

Step-by-step:

1. Download and install ADB Tools on PC.
2. Turn on USB Debugging on Mi 9: Settings → About Phone → MIUI Version (Tap 7 times) → Return to Settings → Additional → For Developers → Debugging on USB
3. Connect your smartphone to your PC and confirm the debugging permission.
4. Open the command prompt (or PowerShell) and type: Adb devices Make sure the device is defined.
5. Execute the command to disable fast charging: adb shell settings put global battery_charging_control 1
6. Reset the device.

To return fast charging, use the command:

adb shell settings put global battery_charging_control 0

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Before using ADB, back up your data via Settings → Additional → Backup and Reset. In rare cases, incorrect commands can cause the system to crash.

Method 4: Third-party applications for charging control

If you don't want to dig into settings or use ADB, you can use specialized applications that not only turn off fast charging, but also set charge thresholds (for example, stop charging by 80%).

Top.-3 tested applications:

• 📱 AccuBattery monitors battery health and allows you to limit the charging current.
• 🔌 Battery Charge Limit – sets a charge limit (e.g. 80%) and reduces charging speed. Requires root to work properly.
• ⚡ Quick Charge Switcher - Directly disable fast charging (does not work on all devices.

Example of settings in AccuBattery:

1. Install the app from Google Play.
2. Go to the Charging section.
3. Activate the option to limit the charging current (Charge current limit).
4. Set the value of 1000 mA (standard charging).

⚠️ Attention! Apps like Battery Charge Limit require root rights to work properly, without which they can only monitor the charge, but not control it.

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Third-party apps are the safest way to control charging, but they don’t give a 100% guarantee to disable Quick Charge. ADB.

What do you do if nothing works?

If none of these methods helped to turn off fast charging, it is possible that the problem lies in one of the following factors:

• 🔄 Firmware – some custom or regional versions MIUI They block access to charging settings. Solution: upgrade to the latest official firmware.
• 🔌 Charger - if you use a non-original power supply, it can ignore the settings of the smartphone.Solution: try charging the device from another adapter.
• 🛠️ Damaged power controller - if the smartphone always charges at top speed regardless of settings, it may indicate a hardware malfunction.
• 📱 Resetting settings – in rare cases, a full reset to factory settings helps (Settings) → Additionally. → Recovery and reset) Attention: all data will be deleted!

If you suspect a hardware problem, check for the following symptoms:

If neither method worked and the battery continues to wear out quickly, consider replacing the battery.For the Xiaomi Mi 9, the original batteries cost around 1,500–2,500. ₽, Replacement at the service center will cost 1000-1500 ₽.

Alternative ways to extend the life of the battery Mi 9

Turning off fast charging isn't the only way to save the battery, but here are some more proven recommendations:

• 🔋 Keep the charge in the range of 20-80% – avoid full discharge and charge to 100.
• 🌡️ Avoid overheating - do not use your smartphone while charging for games or videos.The optimal battery temperature is 10-35°C.
• 📵 Turn off background processes – apps like Facebook, Instagram or instant messengers are constantly synced and drain the battery.
• 🔄 Update the firmware - in new versions MIUI It's often power optimised. Up-to-date version for Mi 9: MIUI 14 (Android 12).
• ☀️ Avoid direct sunlight – overheating in the sun harms the battery more than fast charging.

You can also use the “Optimized Charging” function (if available in your firmware):

Settings → Battery → Settings → Optimized charging

This option automatically stops charging by 80% and only brings it up to 100% before you are supposed to disconnect from the network (based on your habits).

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Combining fast charging shutdown with optimized usage mode can extend the battery life of the Mi 9 by 30-50% longer than standard life (2-3 years).

FAQ: Frequent questions about fast charging on Xiaomi Mi 9