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

Why the Redmi Note 8T Battery Is Drying Faster and How to Fix It

Xiaomi Redmi Note 8T with a battery capacity of 4000 mAh when used actively should keep a charge for at least a day. But over time, even high-quality lithium-polymer batteries degrade: after 300-500 charging cycles, their real capacity can fall by 20-30%. If your Redmi Note 8T began to discharge in a few hours, overheats when charging or suddenly shuts down at 20-30% charge, these are sure signs of battery wear.

In this article, you will learn how to check the battery status on the Xiaomi Redmi Note 8T without disassembling the device. We will look at official methods (hidden engineering menus, MIUI Diagnostics), third-party applications (AccuBattery, AIDA64), as well as physical signs that can determine the degree of wear. Importantly, some methods require unlocking the bootloader or root rights - we will separately specify where this is necessary.

⚠️ Attention: If the battery is swelling (the body of the smartphone has deformed), immediately stop using the device! Lithium polymer batteries in this state can ignite.

Method 1: Check through the engineering menu (#4636##)

The fastest way to get basic battery information is to use a hidden engineering menu, which is available on all Xiaomi smartphones without any additional apps. 8T sequence:

1. Open the Phone app.
2. Enter the combination: ##4636## (no call required – the menu will open automatically).
3. Select Battery Information (Battery Information).

In this section, pay attention to the following parameters:

• 🔋 Level of charge (level) – current percentage in digital form (may differ from the one displayed in the status bar).
• 🔌 Power source – shows whether the charger is connected (AC — network, USB — computer).
• 📊 Health - this can be Good (good) or Unknown (uncertain). 8T This parameter is often not displayed correctly.
• ⚡ Voltage is the norm for the Redmi Note 8T 100% charge: 4.35-4.40 V. If the value is below 4.20 V at full charge, the battery is worn out.
• 🔄 Technology – Li-polymer (lithium polymer battery) must be specified).

⚠️ Warning: If the battery voltage at 100% charge exceeds 4.45 V, this may indicate a faulty charging controller.

Method 2: Diagnostics with MIUI Diagnostics (without root)

Xiaomi has built a hidden diagnostic tool called MIUI Diagnostics into MIUI, which provides more detailed information about the battery than the engineering menu, and activates it:

1. Open the Settings. → The phone.
2. Click 5-7 times in a row on the MIUI version until you become a developer!
3. Go back to the main Settings menu and select a new section for developers.
4. Activate the MIUI Diagnostics switch (could be called System Diagnostics).
5. Go back to the settings → About the phone → All the features.
6. Click on the battery icon (or battery status).

On this menu you will see:

• 📉 Current capacity: Real charge in mAh (e.g., 3200 mAh instead of 4,000 mAh in a new battery).
• 🔋 Design capacity – factory value (4000 mAh for Redmi Note) 8T).
• 🔄 Charge cycles – if the value exceeds 500, the battery is close to complete wear and tear.
• 🌡️ Temperature – Normal: 25–40°C. Exceeding 45°C critically!

💡 Useful advice: If the section MIUI Diagnostics missing, update the firmware to the latest version. MIUI 11 and below this tool may not be available.

Charge your smartphone to 100% | Disable all background apps | Check the body temperature (should not exceed 30°C) | Use the original cable and charger |Write down the current metrics for comparison-->

Method 3: Monitoring applications (AccuBattery, AIDA64, CPU-Z)

Third-party applications provide more accurate battery health data than standard MIUI tools, and we recommend three proven utilities:

📌 Instructions for AccuBattery (the most accurate version):

1. Install the app from Google Play.
2. Charge your smartphone to 100% and connect to charging for another 1 hour (for calibration).
3. Open AccuBattery and go to the Health tab.
4. Notice Estimated capacity, if it's below 3,000 mAh, the battery is worn out.
5. In the Charging tab, check the charging speed. For the Redmi Note 8T, the norm is 15-18 watts.

⚠️ Note: AccuBattery requires 2-3 full charge-discharge cycles for precise calibration.Do not make a decision to replace the battery after the first test!

Method 4: Checking through ADB (for advanced users)

If you're willing to work with ADB, you can get advanced battery data, including actual capacity and number of cycles, which doesn't require root, but you need minimal command line skills.

📌 Step-by-step instruction:

1. Install ADB and Fastboot Tools on your computer.
2. Turn on the smartphone debugging by USB (Settings → For developers).
3. Connect the Redmi Note 8T to your PC and type in the command line: adb shell dumpsys battery
4. Level: 100 voltage: 4387 temperature: 304 capacity: 3500 Here capacity is real capacity in mAh.

🔍 Decoding of key parameters:

• Level is the current charge in %.
• Voltage is the voltage in millivolts (4387 mV = 4.387 V).
• Temperature is a temperature in tenths of a degree (304 = 30.4°C).
• Capacity is the actual battery capacity in mAh (critical parameter).
• charge_counter — charge meter (shows how many mAh the battery has given since the last charge).

⚠️ Note: If the capacity is less than 2500 mAh, the Redmi Note battery 8T It is worn out by 40% or more, and in this case, replacement is recommended, as further degradation will accelerate.

💡

If ADB issues a “device unauthorized” error, check the USB debugging permission request on your smartphone screen and confirm it.

Method 5: Physical signs of battery wear

It doesn't always take programs or codes to know if the Redmi Note 8T battery is failing, and experienced users can tell by the signs of wear and tear.

• 🔥 Overheating – if the smartphone case heats up above 40°C when simply charging or using social networks, it is a sign of degradation.
• 📉 Sudden shutdowns – the phone turns off at 20–30% charge, although the indicator shows a normal level.
• 🐢 Slow charging – instead of 1.5-2 hours, full charging takes 3-4 hours (with a serviceable charger).
• 🔋 Bloating of the case - the back cover or the screen begins to "go away", the smartphone staggers on a flat surface.
• ⚡ Incorrect indicator – the percentage of charge jumps (for example, from 50% immediately to 20%), or the phone shows 100%, but discharges in 10 minutes.

💡 How to check for bloating:

1. Put your smartphone on a flat table with the screen up.
2. You can press the corners of the back cover lightly, and if the case is playing or bending, the battery is swelling.
3. Check if the stitches diverge between the screen and the frame.

⚠️ Attention: A bloated battery is a fire hazard. Don't try to prick it or disassemble your smartphone yourself! Contact Xiaomi Service Center or an authorized workshop.

💡

If a smartphone turns off at 20 to 30 percent charge, it's a sure sign that the actual battery capacity has dropped below 60 percent of the factory's, in which case a replacement is required.

Method 6: Autonomy Test (real time)

The most reliable way to assess the status of the battery is a practical test: fully charge the Redmi Note 8T and use it in standard mode, fixing the time of operation.

• 📵 Turn off mobile internet and Wi-Fi if you are not using it.
• 🔊 Set the screen brightness to 50%.
• 🎮 Do not run games or resource-intensive applications (such as video in the video game). 4K).
• 📞 Use your smartphone in the “medium load” mode: messengers, calls, web surfing.

📊 Autonomousity standards for Redmi Note 8T:

🔋 How to speed up the test:

1. Turn on Airplane Mode.
2. Run the video on YouTube at 1080p resolution at full brightness.
3. Take a look at the time it takes to drop from 100% to 0%, and it's 5-6 hours for a new battery, and 2-3 hours for a worn one.

What to do if the battery is worn out?

If the diagnostics showed that the battery capacity of the Redmi Note 8T fell below 70% of the factory (less than 2800 mAh), consider the following options:

• 🔧 Official replacement - in the service center Xiaomi (warranty 6 months, price) ~2500–3500 ₽).
• 🛠️ Unofficial repairs – in workshops (cheaper, but risk of poor quality battery).
• 🔋 Self-replacement - only if you have experience disassembling smartphones (need a soldering iron, glue, special tools).
• 📱 Software optimization – disabling background processes, transition to MIUI Lite, using a dark theme.

⚠️ Note: When replacing the battery with a Redmi Note 8T necessarily:

• Use the original battery with the MB-J21 item (or a similar one from proven manufacturers, such as ZOP Power).
• Check that the new battery has a protective circuit (charging controller).
• After replacement, perform calibration: completely discharge and charge the smartphone 2-3 times.

💰 Cost of replacement (2026):

• Original battery: 1800–2500 ₽ (independently / 3000-4000 ₽ (service).
• Analogue (quality): 1200–1800 ₽.

💡

Replacing the battery in informal workshops can cause the case to lose leakage and dust to get under the screen. Choose services with a guarantee of at least 6 months.

FAQ: Frequent questions about the Redmi Note battery 8T