Modern smartphones such as the Xiaomi Redmi 9T are equipped with powerful 6,000 mAh batteries and support Quick Charge 3.0 fast charging technology. This allows you to restore the energy of the device in the shortest possible time, which is extremely convenient for active users during the day. However, in some situations, high current intake speed can cause excessive heating of the case or adversely affect the long-term degradation of battery chemicals during night use.
Many owners are wondering if you can forcefully limit the power supplied to the battery to charge the gadget slower and safer. Unfortunately, the standard settings menu of the operating system MIUI or Android does not have a switch that would completely disable the fast charging protocol by software.
However, there are proven ways to get around this limitation: You can use specialized cables, third-party chargers with less current, or software crutches through ADB-In this article, we will take a closer look at all the available methods, their pros and cons, and explain why, in some cases, avoiding fast charging is a smart step to keep your Redmi healthy. 9T.
Why you should limit the speed of charging
The main reason why users are looking for ways to turn off fast charging is heat generation. The process of pumping energy into a lithium polymer battery is always accompanied by heat generation. The higher the current, the more intense the device heats up. In the Redmi 9T model, despite its efficient cooling, the temperature can reach critical values when using the original power supply, especially if the smartphone is lying on a soft surface.
Long-term exposure to high temperatures leads to irreversible changes in the structure of the battery electrolyte, which means reducing maximum capacity and reducing the total number of recharge cycles. If you used to leave your phone on charge all night, it does not need fast charging, it will already have time to charge in the first couple of hours, and the rest of the time will simply warm up, receiving microdoses of current.
⚠️ Warning: Constant overheating of the battery above 40 degrees Celsius significantly accelerates the aging process.If you often notice that the smartphone is hot while charging, abandoning the Quick Charge will be a great solution.
In addition, there are situations where the electrical network is unstable, and surges in voltage combined with high charging current can damage the power controller.Using a more gentle charging mode reduces the load on the entire electronic board of the smartphone, extending the life of not only the battery, but also other components.
Use of alternative chargers
The easiest and safest way to turn off fast charging on the Xiaomi Redmi 9T is not to use the original power supply.The Quick Charge protocol is activated only when the charger and smartphone “agree” to increase voltage or current. If you connect the smartphone to a power supply with 5V/1A or 5V/2A characteristics, fast charging simply will not turn on.
Many older chargers from previous phones or other gadgets have these parameters, and if you plug a Redmi 9T into that unit, you'll see a standard battery icon on the screen without saying "Quick Charge" or "Turbo Charge," the power rate will decrease, but the device will remain cold.
- 🔌 Old power supplies: Find an adapter with an output current of no more than 2 Amps (10W).
- 💻 USB-Computer port: Charging from the port USB 2.0 or 3.0 on a PC or laptop is usually limited to 0.5A or 0.9A currents respectively, which excludes any fast charging.
- 🚗 Car Charging: Many car adapters don’t support Xiaomi’s fast charging protocols and will charge your phone as normal.
This method does not require any technical knowledge and does not carry risks for the software part of the smartphone.The only drawback is that the full charging time can increase from 2-3 hours to 4-5 hours or more, which is not always convenient in time conditions.
The effect of cable on the current transfer rate
Keep in mind that the cable plays a key role in the charging process. The Quick Charge 3.0 mode on the Redmi 9T requires a cable that can pass current up to 3 Amps or higher. If the wire has high resistance or is damaged, the smartphone will automatically limit the incoming current for safety.
You can use thin or long cables of poor quality that are not designed for high currents, in which case the power controller will determine that fast charging is not safe and switch to standard mode, but this approach is not recommended to use constantly, as bad cables can warm themselves and create voltage surges.
A better solution would be to use a quality, but short cable that structurally does not support high currents, although it is becoming increasingly difficult to find one on sale. Most modern USB Type-C cables are originally designed with a margin of safety.
⚠️ Note: Do not use cables with damaged insulation or oxidized contacts.This can short-circuit or damage the charging port, regardless of the current supply rate.
Too long cables (more than 2 meters) without proper shielding and thickness of the wire can cause a voltage drop, which will also lead to a shutdown of fast charging, but will make the process unstable.
Software Restrictions via ADB (for Advanced Users)
For those who are not afraid to work with code and want to gain programmatic control over the process, there is a method of using Android Debug Bridge (ADB), which allows you to send commands directly to the Android system, bypassing the standard interface, and with this you can try to change the parameters of the charge controller, although modern versions of MIUI access to them is often closed.
To start, you need to turn on the developer mode on your Redmi 9T. To do this, go to Settings → About your phone and quickly click 7 times on the MIUI version. After that, a new section will appear in the menu "For developers", where you need to activate debugging over USB.
Connect your smartphone to your computer, install ADB drivers, and try to run a command to check battery status. However, it's worth noting that direct commands to disable QC often require root rights. Without superuser rights, you can only monitor status.
adb shell dumpsys batteryThis command will show the current battery status, charge level and connection status. If you have root rights, you can try changing the current limit, but this is individual for each power controller and requires a deep knowledge of your device model.
Risks of using ADB teams
Comparison of methods of shutting down fast charging
To make it easier for you to choose the right option, we have prepared a comparative table of basic methods, each of which has its own characteristics that should be considered depending on your goals and equipment availability.
| Method | Difficulty | Security | Charging speed |
|---|---|---|---|
| Power supply 5B/1A | Low. | Tall. | Very low. |
| USB-port | Low. | Tall. | Low. |
| ADB team | Tall. | Medium | Depends on the setting. |
| Thin cable | Low. | Medium | Medium/Low |
As you can see from the table, using weak power supplies or computer ports is the safest and easiest way, software methods require technical training and do not provide 100% guarantee on all versions of MIUI firmware.
If your goal is simply to extend the life of the battery, the combination of "old unit + quality cable" will be the best choice, which ensures that the power controller will not work in overload mode, and the temperature of the case will remain comfortable.
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The most reliable way to turn off fast charging without risk to the system is to use a low-out current charger (less than 2A).
Battery Optimization Settings in MIUI
Although there is no direct fast-charging switch, MIUI has charge optimization features that can indirectly affect the process. In Settings → Battery → Battery Saving, you can activate energy saving modes.
When power saving mode is enabled, the system limits the background activity of applications and may slightly reduce the performance of the processor, which reduces the overall heating of the device during charging.
Also worth paying attention to is the Optimized Charging feature (if available in your version of the software), which learns your habits and can pause charging at 80%, only completing the process by the time you wake up, which reduces the battery time under high voltage.
- 🔋 Flight mode: Turning on the air mode during charging turns off communication modules, which reduces heating and slightly speeds up the process, making it more stable.
- 📱 Screen off: Do not use your smartphone actively while charging, so as not to provoke additional heating.
- ❄️ Refrigeration: Remove the case while charging for better heat sink, especially if you haven't been able to turn off fast charging.
Remember, software optimization is a secondary measure, and it doesn't replace the physical restriction of incoming current, but it helps keep the device in a more comfortable temperature.