Owners of the Redmi Note 8 2021 often face situations where the standard battery power recharge rate becomes excessive or even undesirable. While Quick Charge technology can significantly reduce the waiting time at the outlet, at night or when using the device as a stationary navigation, high power can lead to excessive heating of the case.
In addition, constant work at limit currents can accelerate the physical wear of a lithium polymer battery, reducing its capacity in the long run, which is why the question of how to forcely limit the charging speed or completely turn off its accelerated mode becomes relevant for many users who want to extend the life of their gadget.
In this article, we will discuss in detail the software and hardware solutions to this problem, you will learn what settings of the MIUI system can be changed, how to use the hidden engineering menu, and whether you should use third-party software to control incoming current.
Why it is necessary to limit the charging speed
The main reason users want to slow down is heat generation. When the smartphone is charged at its maximum power (18 watts for this model), the chemical reactions inside the battery are more intense, which inevitably leads to a rise in temperature. If the device is in a case or lying on a soft surface, heat removal is difficult, which creates stressful conditions for the cells of the battery.
Another important aspect is using a smartphone as a stationary terminal or a smart home control panel, in which the rate of energy replenishment does not matter, the main thing is the stability and absence of voltage surges that can occur when fast-charging algorithms are activated. The usual mode provides a smoother and more gentle current profile.
⚠️ Warning: Constant battery overheating above 40 degrees Celsius is the main lithium cell malignancy. Limiting charging speed is an effective way to reduce thermal load.
It is also worth considering that some users simply prefer to charge the device in the background during the working day, connecting to the device. USB-In this case, the system itself will not turn on acceleration mode, but understanding the principles of the power controller will help to better manage energy consumption.
Software Restrictions through MIUI Settings
The first thing you should check for the owner of the Redmi Note 8 2021 is the standard system settings. Although the direct button “Disable Fast Charging” is often not in the usual menu of the MIUI interface, there are related parameters that affect the behavior of the power controller, primarily talking about optimizing night charging.
Find Settings → Battery → Battery Protection on the menu, and it may have Optimized Night Charging, which doesn't shut down the fast current completely, but artificially slows down the process at certain hours to complete it by the time you wake up, which reduces the time the battery spends at maximum voltage.
You also need to pay attention to the mode of operation of the processor. If you turn on the Saving Power mode, the system can programmatically limit not only the background activity of applications, but also the aggressiveness of charging to minimize heating. This is an indirect but working method for those who do not want to go into deep settings.
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Use Flight mode while charging if you don’t need notifications, which will reduce the load on the radios and reduce the overall heat of the device, allowing the power controller to operate in a more relaxed mode.
Using the Engineering Menu for Testing
For more advanced users, there is access to the hidden MIUI engineering menu, which allows you to diagnose battery status and sometimes influence charging parameters. However, it is worth noting that in modern versions of firmware, direct shutdown of QC (Quick Charge) from here is often blocked by the manufacturer for security reasons.
To get to the menu, open the Phone app and dial the combination ##6484##. You will see the list of tests. We are interested in the section related to the battery (usually Battery info or Version), Here you can see the current status: whether the phone is charging via USB, what current is consumed and whether the fast charging protocol is activated.
If you have a Charger Config menu in your region or firmware version, you can see switches for different modes. But even if you don't have a direct lock, monitoring those settings will help you understand when the fast mode is on, for example, you'll notice that when the screen is off, the current is higher than when you're using it.
What if the code doesn't work?
Application of third-party controller applications
Since Xiaomi’s standard tools don’t always ban fast charging, specialized apps from the Google Play store come to the rescue. AccuBattery is the most popular and effective solution. It can’t physically disable the handshake protocol between the charger and the phone without root rights, but it does a great job of monitoring and alerting.
The way these programs work is by monitoring the current in real time, and the app shows you what current is going to the battery. If you see values above 1.5-1.8 A, you can use fast charging. Using smart charging alarms, you can set the phone to sound when the current is above a predetermined threshold, hinting at turning off the cable or changing the adapter.
For Root-enabled devices (e.g., Magisk), there are modules that can programmatically limit the maximum charging current at the core level, the most effective method for setting a hard limit of, say, 1,000 mA, regardless of the capabilities of the connected power supply.
- 📱 AccuBattery is the best tool for monitoring battery health and tracking current charging speeds in real time.
- 🔋 Battery Charge Limit – an application for advanced users (requires Root), allowing you to set strict limits on the current charge.
- ⚡ 3C Battery Manager is a powerful power management combine that supports the creation of profiles for different use cases.
⚠️ Warning: Installing deep-access applications or obtaining Root rights may void the warranty on the Redmi Note 8 2021 device. Act carefully and back up data.
Hardware Method: Choosing the Right Adapter
The easiest, most reliable and safest way to turn off fast charging on the Redmi Note 8 2021 is to use an inappropriate charger. Rapid charging protocols such as Qualcomm Quick Charge or USB Power Delivery work on the principle of matching: the phone “quess” the power supply if it can give more current, and the unit “responds” by increasing voltage or current.
If you connect your smartphone to a regular 5W adapter (old charges from iPhone or simple button phones) or to a mobile phone. USB-The phone will charge at a standard speed of 5 volts and 1 ampere (or 0.5 ampere for old ports). USB This is guaranteed to eliminate any overheating and provide the most gentle mode for battery chemistry.
There are also special limiter cables or cables without an identification chip that physically prevent the signal from transmitting high current support, and using such a cable with a powerful power supply will force the unit to operate in base mode.
☑️ How to Choose an Adapter for Slow Charging
Comparison of charging modes and their effect on the battery
To help you weigh the pros and cons, let’s take a look at the comparison table of different charging scenarios for the Redmi Note 8 2021, which will help you understand which method is best for your specific needs.
| Parameter | Fast Charging (QC 3.0) | Regular charging (5B/1A) | Charging from a USB PC |
|---|---|---|---|
| Power | 18W | 5 watts | 2.5 - 4.5 W |
| Charge time (0-100%) | ~1 h 40 min | ~3 hours | ~4-5 hours |
| Heating the hull | High-pitched | Low. | Minimum |
| Battery wear and tear | Accelerated | Standard. | Minimum |
As you can see from the table, sacrificing speed gives us a significant gain in temperature and presumably battery life. For overnight charging, when there is no rush, using a conventional 5W adapter is the ideal solution.
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The most effective way to disable fast charging without root rights is to use a weak power supply (5V/1A) or USB-computer port. software methods in MIUI are often restrictive in nature.