Xiaomi Redmi 8 battery calibration: a complete guide with step-by-step instructions

The Xiaomi Redmi 8 battery is one of the key components that determines the battery life of the device. Over time, many users notice that the battery starts to drain faster, and the percentage of charge is displayed incorrectly: the phone suddenly turns off at 20-30% or, conversely, charges up to 100% in a matter of minutes. These symptoms often indicate a dissynchronization of the power controller and the real state of the battery.

In this article, we will discuss what calibration is, why it is necessary for the Redmi 8 (especially after prolonged use or battery replacement), and provide step-by-step instructions for all available methods. You will also learn how to avoid typical errors that can aggravate the problem, and what to do if the calibration did not help. It is important to note that the procedure will not restore the physically worn battery, but will return accurate charge readings and optimize its performance.

What is a battery calibration and why is it needed?

Calibration is the process of synchronizing data between the charge controller (the power management microchip) and the actual state of the battery. The Xiaomi Redmi 8 uses a 5,000 mAh lithium polymer battery that loses some of its capacity over time due to natural wear and tear, and the controller continues to operate on the original data, leading to inaccurate readings.

The main signs that the battery is time to calibrate:

• 🔋 The phone turns off when it's off. 15-30% The charge, although it should work longer.
• ⚡ Charging to 100% is too fast (less than 1 hour).
• 📉 The percentage of charge "jumps" (for example, from 40% immediately to 15%).
• 🔄 After battery replacement, the readings are unstable.

Calibration will not increase the physical capacity of the battery, but it will help:

• 📊 Precisely display the charge level.
• ⚡ Optimize charging/discharge cycles.
• 🛠️ Extend the battery life due to the correct operation of the controller.

⚠️ Warning: If the battery is swollen, deformed, or the phone overheats while charging, calibration won't help - battery replacement is required!

Calibration Preparation: What to Do in Advance

Before starting the procedure, you need to follow several important steps to avoid failures and damage the battery. First, make sure that you have an original or quality charger (preferably from Xiaomi with Quick Charge 3.0 support).

Check the status of the battery:

• 🔍 Check the battery for swelling (if it is removable).
• 📱 Make sure your phone doesn’t overheat normally.
• 🔌 Use only the correct one. USB-cable (preferably original).

It is also recommended that:

• 📴 Disable all background applications (Settings) → Annexes → Auto-start).
• 📡 Activate the aircraft mode (Notification Panel) → Airplane mode).
• 🔋 Charge your phone to 100% before the procedure.

Method 1: Calibration through the menu of engineering settings (without ROOT)

This is a good way for most Redmi 8 users, because it doesn't require super-user rights. The engineering menu is hidden in the system, but it can be accessed through secret code.

Instructions:

1. Open the phone app and enter the combination: ##4636##
2. In the menu that opens, select Battery Information.
3. Click on Battery Calibration (if there is no option, proceed to the next method).
4. Connect your phone to charge and wait for 100% charge.
5. Turn off charging and discharge the device until it is automatically turned off.
6. Charge your phone back to 100% without interruption.

Enter the code ##4636##

Check the charge level in the menu "Battery Information"

Connect the original charging

Discharge the phone before it turns off

Repeat the charging cycle without interruption-->

⚠️ Note: If after calibration the phone is still turned off when 20-30% The problem with the battery is that it's physically worn out, and then the only thing that helps is to replace it.

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If the option "Battery Calibration" is not in the engineering menu, try using the application AccuBattery from Google Play. It analyzes the state of the battery and offers optimal charging cycles.

Method 2: Calibration through a full charge/discharge cycle

This method is universal and works on all smartphones, including the Xiaomi Redmi 8. It does not require special knowledge or ROOT rights, but will take longer (about 6-8 hours), the essence of which is to completely discharge and then charge the battery without interruption.

Step-by-step:

1. Charge your phone to 100% and leave it on charge for another 1-2 hours (to stabilize).
2. Turn off charging and use the device as normal until it turns off on its own (do not turn it on until it is completely discharged!).
3. Connect your phone to charge and charge up to 100% without interruption (don’t turn off the cable!).
4. Repeat the cycle 2-3 times for better results.

Important nuances:

• 🕒 Discharge time should be at least 4-5 hours (artificial acceleration of the process is unacceptable).
• 🔌 Use only original charging (18W for Redmi 8).
• 📵 Turn off Wi-Fi, mobile data and GPS, quicken.

Method 3: Calibration with TWRP (for advanced users)

If standard methods don't work, and you have custom recovery TWRP, you can use a deeper calibration, which requires an unlocked bootloader and a TWRP installed, but it gives you better results.

Instructions:

1. Turn off the phone and press Power + Volume up to enter TWRP.
2. Go to Advanced → File Manager.
3. Find the file /data/system/batterystats.bin and delete it.
4. Restart your phone in normal mode.
5. Complete a full charge/discharge cycle (as in Method 2).

After deleting the batterystats.bin file, the system will create a new one that will help to reset incorrect battery data. However, this method is not recommended for beginners, since improper actions in TWRP can lead to data loss or device blink.

⚠️ Attention: Deletion of the file batterystats.bin Reset battery usage statistics in Settings → Battery. This is normal and doesn't affect the operation of the device.

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Calibration via TWRP is the most effective method, but is only suitable for users with an unlocked bootloader and custom recovery installed.

Frequent calibration errors and how to avoid them

Many users make mistakes that negate all calibration efforts, and the most common ones are:

• ❌ Interrupting the charging cycle (e.g., turning off the cable by 80%) results in incomplete synchronization of the controller.
• ❌ Using unoriginal charging. Cheap adapters can give unstable voltages, which distorts the battery data.
• ❌ Artificial discharge (e.g., through an engineering menu or applications) The controller must record the natural discharge.
• ❌ Calibration at low temperature (below 10)°C) This may damage the battery.

How to avoid mistakes:

• ✅ Use only original accessories from Xiaomi.
• ✅ Do not interrupt the charging/discharge cycle.
• ✅ Calibrate at room temperature (15–25)°C).
• ✅ Repeat the procedure every 3-6 months to maintain accuracy.

If the phone still turns off after calibration at 20 to 30 percent charge, that means the actual battery capacity has dropped to 60 to 70 percent of the original battery capacity, in which case the calibration is powerless, requiring a battery replacement.

What to do if calibration does not help

If after all the manipulations the problem persists, the following reasons are possible:

• 🔋 Physical wear of the battery (capacity below 60% of nominal capacity).
• 🛠️ Faulty of the power controller (diagnosis is required in the service center).
• 📱 Software failure MIUI (Helps reset to factory settings).

Actions in each case:

If you are not sure about the cause of the malfunction, you should contact the service center.Self-substitution of the power controller without experience can lead to a breakdown of the motherboard.

FAQ: Answers to Frequent Questions