How to know the battery capacity on Xiaomi Mi 9T: all working methods

Xiaomi Mi 9T (also known as the Redmi K20 in some regions) – a popular smartphone with a capacious battery on 4000 But over time, the actual capacity decreases, if the phone starts to run out faster or suddenly shut down when you're in the middle of a cell. 20-30% It's time to check the battery status — 5 Proven ways to know the current battery capacity, including hidden engineering menus, third-party apps and commands ADB.

It is important to understand the difference between the rated capacity (as indicated on the battery case) and the actual capacity (what is left after wear). For example, if your Mi 9T shows 100% charge but turns off by 35%, this is a signal of severe battery wear (maybe less than 60% of the original capacity remains), we will discuss how to measure this parameter without disassembling the phone.

1. Testing capacity through the engineering menu (#4636##)

The fastest way is to use Android’s hidden engineering menu, which is available on all Xiaomi smartphones, including the Mi 9T, but requires caution: don’t change settings unless you understand their purpose.

Instructions:

1. Open the Phone app.
2. Enter the combination: ##4636## (no call).
3. Select Battery Information (Battery Information).
4. Pay attention to the line Level (current charge in %) and Health (state).

On this menu you will see:

• 🔋 Level of charge (level) – percentage of current capacity.
• 📊 Health – if Good is indicated, wear is minimal; Unknown or numbers below 80% signal a problem.
• 🔌 Temperature (Temperature) – the norm is 25–40°C, above 45°C is dangerous for the battery.

⚠️ Warning: If the Health menu shows as Unknown, it doesn't always mean a malfunction. MIUI This is not supported. Try alternative methods.

Check the correctness of the code entry (#4636##)

Update your firmware to the latest version of MIUI

Try entering the code through Google’s Dial-Up app (install from Play Market)

Reboot the phone.-->

2.Use of the AccuBattery application (exact analysis)

AccuBattery (available on Google Play) specializes in monitoring battery status, not only showing current capacity, but also analyzing charging cycles, temperature and wear rate. For the Xiaomi Mi 9T, it is one of the most reliable tools.

How to use:

1. Install AccuBattery from Play Market.
2. Charge the phone to 100% and connect to charging for another 15 minutes (for calibration).
3. Open the app and go to the Health tab.
4. Please note the graph Estimated Capacity.

What does the data in AccuBattery mean:

AccuBattery also shows real charging current (in mA), which is useful for checking the serviceability of the cable or adapter. For example, if your Mi 9T supports Quick Charge 4+, but the current does not exceed 1000 mA, the problem may be in the charger.

Once a month

Once in 3 months

Only when the problems start.

Never calibrated.-->

Verification through ADB (for experienced users)

If the engineering menus and apps don't give you accurate data, you can use ADB (Android Debug Bridge), which requires connecting the phone to a computer, but gives you the most detailed information about the battery, including the actual capacity in mAh.

Step-by-step:

1. Turn on USB Debugging on your phone: Go to Settings → About Phone. Tap 7 times on MIUI to activate Developer Mode. Go back to Settings → Additional → For Developers and enable USB Debugging.

Mi 9T

Open the command line (Windows) or terminal (macOS/Linux) and type:

adb shell


dumpsys battery

In the conclusion, find the lines:

• charge counter - current charge in μAh (divided by 1000 to get mAh).
• Capacity is the percentage of charge.
• Health is the battery state (2 = Good, 3 = Overheat, 7 = Dead).

Example of output for Mi 9T with worn-out battery:

charge counter: 2800000 (2800 mAh at 100% charge)


health: 3 (overheating or severe wear)

⚠️ Note: If the charge counter value at 100% charge is less than 3000 mAh, the battery is severely worn out.A value below 2500 mAh is recommended to replace, as Mi Mi is recommended. 9T It will be turned off at 40-50% charge.

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If ADB does not recognize the device, install Xiaomi USB Drivers from the official website or through the Mi Unlock Tool.

4. Battery Test Codes (Hidden Xiaomi Menu)

Xiaomi hides several utility codes for diagnosing the battery, which work on most models, including the Mi 9T, but may vary depending on the version of MIUI.

List of useful codes:

• 📱 ##6484## - battery test (shows voltage, temperature, state).
• 🔋 ##64663## - Battery diagnostics menu (on some firmware).
• 🔍 ##284## - charging test (checks current and voltage).

After entering the code ##6484##, you will see a screen with the following parameters:

• MB_06 — battery voltage (normal) 3.7–4.2 V).
• MB_01 — temperature (in degrees, multiply by 0.1).
• MB_05 — status (good, place soon or place now).

If the menu displays Replace now, the battery is worn out by more than 50% and needs to be replaced. On the Mi 9T with this battery, the battery life is reduced by 2-3 times.

Calibration of the battery (if the data are inaccurate)

Sometimes the smartphone shows the wrong percentage of charge because of a failure of the battery controller, and in this case, calibration, a procedure that resets the data about the charging cycle, will help, and this will not restore the capacity, but will return accurate readings.

How to Calibrate the Battery on Xiaomi Mi 9T:

1. Discharge the phone before automatically switching off (0%).
2. Connect to the original charger and charge for at least 8 hours without interruption.
3. Turn off the charging, turn on the phone and wait for the full load.
4. Repeat the discharge/charging cycle again.

After calibration:

• 🔄 The percentage of charge will be more accurate.
• ⚡ The phone will stop suddenly turning off at 10-20%.
• 📉 If the problem persists, the battery is physically worn out.

⚠️ Attention: Calibration only helps with software failures. 9T It's down to 70 percent, and no calibration will bring back the time it used to work, so you need to replace the battery. MB-J30).

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Calibration doesn't restore capacity, it only corrects the charge display errors, and if the phone still discharges quickly after the procedure, the problem is the battery's physical wear and tear.

6 When is the time to change the battery to the Mi 9T

Even when used with care, the Xiaomi Mi 9T battery loses capacity over time, and here are signs that the battery needs to be replaced:

• 🔋 The phone discharges in 3-4 hours with moderate use (previously held the day).
• ⚡ Charging reaches 100% in 20-30 minutes (controller cheats due to low real capacity).
• 🔌 The device shuts down at 30-40% charge or does not turn on without connecting to the network.
• 🌡️ The battery is very hot (above 50).°C) even under light load.
• 📉 In applications like AccuBattery, the capacity is less than 2,500 mAh.

The cost of replacing the battery with the Mi 9T:

When replacing the battery, pay attention to:

• 🔧 Guarantee – in official services give 6-12 months.
• 🔋 Capacity - the original battery should be 4000 mAh (the body is marked with a brand) ATL or SDI).
• 🛠️ Clay's at Mi. 9T battery glued, to replace need a hair dryer and plastic blades.

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Before replacing the battery, back up your data via Settings → System → Backup. When disassembling the phone, there is a risk of damage to the display plume.

FAQ: Frequent questions about the Xiaomi Mi battery 9T