How to check the battery status on Xiaomi Redmi Note 8T: from the code *#*#4636#*#** to the diagnosis through ADB

Xiaomi Redmi Note 8T is a popular smartphone with a capacious battery of 4000 mAh, but over time, even the best battery deteriorates. If your device began to run out in a few hours, overheat when charging or suddenly turn off at 20-30% charge are the sure signs of wear. In this article, we will examine all the available ways to check the battery on the Redmi Note 8T, from hidden engineering menus to professional diagnostic utilities.

It's important to understand that battery performance is not just dependent on the number of charging cycles, but also on operating conditions: temperature, fast charging, quality of cables and adapters. We'll show you how to get accurate data on the actual capacity, number of cycles and cell condition without disassembling the device or special equipment.

1. Check through the engineering menu (#4636##)

The fastest way to get basic information about the battery is to use a hidden engineering menu, which is available on all Xiaomi smartphones without root rights and additional applications.

  1. Open the Phone app.
  2. Enter the combination: ##4636###.
  3. In the menu that appears, select Battery Information.

Here you will see the key parameters:

  • πŸ”‹ Level of charge (level) – current percentage in digital form.
  • πŸ”Œ Power source: battery (from battery) or USB/AC (charge-free).
  • ⚑ Voltage is the norm for the Redmi Note 8T 3.7-4.3 V. If the value is below 3.5 V at 100% charge, the battery is critically worn out.
  • 🌑️ Temperature (optimal 25–40)Β°C. Exceeding 45Β°C when charging indicates degradation.

⚠️ Note: The engineering menu shows current values, not historical data. To assess wear, you need to compare the voltage at 100% charge with the reference 4.3-4.4 V.

πŸ’‘

If the engineering menu doesn’t open, try entering the code through the standard Phone app, not through third-party calls. On some MIUI firmware, you may need to pre-disable the Settings β†’ Special Features β†’ Access menu.

2.Use code ##6484## for battery test

A little-known service code ##6484## runs a test of hardware components, including the battery, which provides more detail than the engineering menu, but doesn't work on all versions of MIUI.

  1. Enter in the call: ##6484##.
  2. Select the Battery Test (also known as the MBAT Test).
  3. Wait for the diagnosis to be completed (1-2 minutes).

In the results, pay attention to:

  • πŸ“Š Capacity - compare with passport 4000 mAh. If the value is below 3000 mAh, the battery requires replacement.
  • πŸ”„ Cycle count – more than 500 cycles are considered critical wear.
  • ⚠️ Status – Good (normal), Weak (weak), Replace (requires replacement).
ParameterNorm for Redmi Note 8TCritical significance
Capacity (mAh)3800–4000< 2500
Voltage (B)3.8–4.3< 3.5 or > 4.5
Temperature (Β°C)25–40> 50
Charging cycles< 300> 600

⚠️ Attention: On some firmware MIUI 12+ The code ##6484## can be blocked, in which case use alternative methods from the following sections.

πŸ“Š How often do you check the battery status?
Once a month
Only when problems arise
Never checked.
I don't know how to do that.

3. Diagnostic applications: AccuBattery and AIDA64

If the service codes don't work or don't provide enough data, third-party utilities come to the rescue. Two of the most reliable applications for the Redmi Note 8T:

AccuBattery (free, with premium options)

AccuBattery analyzes the actual battery capacity, discharge rate and wear.

  • πŸ“ˆ Shows actual capacity (e.g. 3200 mAh instead of the declared 4000).
  • πŸ”‹ Monitors battery health as a percentage (100% = new, <80% = critically).
  • ⚑ Monitors the current of charging / discharging in mA.

How to use:

  1. Install AccuBattery from Google Play.
  2. Charge your phone to 100% and wait for the calibration (1-2 cycles).
  3. Check the Health tab for wear data.

AIDA64 (paid but trial-period)

AIDA64 provides the technical specifications of the battery, including factory data.

  1. Open the app and go to the Battery.
  2. Check the fields: Battery type (should be Li-polymer). Temperature and voltage. Status (Unknown means the data is not readable).

Charge your phone to 100% | Disable battery optimization for the application |Use the original cable |Do not interrupt the charging/discharge cycle-->

4. Check through ADB (for advanced users)

If you want the most accurate data, including factory capacity and cycle count, use ADB (Android Debug Bridge), which requires a computer and minimal technical skills.

Instructions:

  1. Download ADB Tools and install drivers for Xiaomi.
  2. Enable USB Debugging in the Developer Settings (Settings β†’ About Phone β†’ MIUI Version – Press 7 times, then return to Additional β†’ For Developers).
  3. Connect your phone to your PC and execute the commands: adb shell dumpsys battery

In the conclusion, find the lines:

  • Capacity is the current charge in %.
  • Voltage - voltage in ΞΌV (divided by 1000 for volts).
  • Temperature: temperature in Β°C (divided by 10).
  • charge_counter β€” the approximate capacity in mkAh (divided by 1000 for mAh).
How to decipher ADB output?
The line health: 2 means that the battery is fine. Values: - 1: Unknown - 2: Good - 3: Overheating - 4: Too cold - 5: Overload voltage - 6: Fault

⚠️ Attention: Teams ADB They give raw data from the sensors. For accurate interpretation, compare it to the reference values in the table in section 2.

5.Visual signs of battery wear

Programs or codes are not always needed, some symptoms of critical wear are visible to the naked eye:

  • πŸ”₯ Bloating the case - if the back cover is Redmi Note 8T Begins to bend or gaps appear between the screen and the frame, the battery must be replaced immediately (the risk of fire!).
  • ⚑ Instant charge drop – for example, from 30% to 0% in a few minutes.
  • πŸ”Œ Slow charging – if the phone charges from 0% to 100% for more than 4 hours (using the original 18W RAM).
  • 🌑️ Overheating – the battery is heated above 50Β°C even in normal use.

If you see any of these signs, it's dangerous to operate a smartphone, and a bloated battery can damage the screen or motherboard, and overheating can lead to fire.

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Battery bloating is an emergency. Don't try to puncture or bend the battery! Turn off your phone immediately and go to the service center.

6. Battery calibration: when and how to do

Sometimes the problem is not wear, but incorrect data from the charge controller. Calibration helps to reset capacitance accounting errors. 8T:

  1. Discharge the phone before automatically shutting down (0%).
  2. Connect the original RAM and charge for at least 8 hours without interruption.
  3. Turn off the charging, turn off the phone for 5 minutes, then turn it on.
  4. Repeat the discharge/charging cycle again.

Calibration helps if:

  • πŸ“‰ The phone turns off at 10-20% charge.
  • πŸ”„ The percentage of charge "jumps" (e.g., from 50% to 30% per second).
  • ⚑ Charging stops at 80-90%.

⚠️ Attention: Calibration does not restore the capacity of the worn-out battery; it only corrects the controller readings. If after calibration problems remain, the battery needs to be changed.

7. When it's time to change the battery: checklist

Replacement of the battery with the Redmi Note 8T is required if:

Capacity below 2500 mAh (62% of the original)|Number of cycles > 600|Bloating of the hull|The phone shuts down at 20-30% charge|Temperatures above 50Β°C to the plain-->

The cost of replacing the battery in Xiaomi service centers is from 1500 to 2500 rubles (2026). Use only original batteries with the MB-J12B article or certified analogues (for example, from ZMI).

If you are replacing the battery yourself, consider:

  • πŸ› οΈ You will need a special glue to fix the new battery.
  • ⚠️ Risk of damaging plumes or motherboard during dismantling.
  • πŸ”§ A plastic mediator is needed to accurately open the body.

πŸ’‘

Self-replacement of the battery is not warranty (if it is still valid). Official service centers Xiaomi provide 6 months warranty for a new battery.

FAQ: Frequent questions about the Redmi Note battery 8T

Can Power Bank be used to calibrate the battery?
No, calibration must necessarily be done from the original network charger.Power Bank does not provide stable voltage, which can skew the results.
Why is AccuBattery 3500mAh and #4636## 4,000mAh?
The service menu displays the passport capacity (factory) and the AccuBattery displays the actual discharge current, a difference of 10-15% is normal for a battery with a wear and tear of 1-2 years.
How to check the battery if the phone is not turned on?
If the Redmi Note 8T is not responding to charging, connect it to your PC and check if it is identified as a device in Device Manager. If so, there is a problem with the firmware or power controller. If not, deep discharge (you need a boost charge) or a break in the battery chain is possible.
How many charging cycles can the Redmi Note 8T battery withstand?
The manufacturer claims 800-1000 cycles to reduce capacity to 80%, and in practice, when used intensively (fast charging, games, heat), the resource is reduced to 500-600 cycles.
Can I use wireless charging for the Redmi Note 8T?
No, the Redmi Note 8T does not support wireless charging at the hardware level, and the use of adapters with a Qi receiver leads to overheating and accelerated wear of the battery.