How to check the battery status of Xiaomi Redmi Note 9 Pro: all ways

The battery is one of the most vulnerable parts of the smartphone, and the Xiaomi Redmi Note 9 Pro is no exception. After 1-2 years of active use, the battery capacity inevitably decreases, leading to rapid discharge, sudden shutdowns and charging problems. But how exactly do you know how worn out your device's battery is? Official MIUI settings hide this information, and third-party applications often show conflicting data.

In this article, we’ll look at 5 proven ways to check battery status on the Redmi Note 9 Pro, from hidden engineering menus to professional utilities. You’ll learn how to interpret wear metrics, when it’s time to change the battery, and how to calibrate it to accurately display charge levels. All methods are tested on current versions of MIUI and do not require root rights (except one advanced method).

⚠️ Note: Some methods (e.g. use) ADB) If you do not perform correctly, follow the instructions carefully and do not change the parameters, the purpose of which you do not know.

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

The fastest way to get basic information about the battery is to use the hidden Android menu, which is available on all Xiaomi smartphones, including the Redmi Note 9 Pro, but not all users are aware of its existence.

To open the menu:

1. Open the Phone app.
2. Enter the combination ##4636## (as a normal number).
3. In the window that appears, select Battery Information.

Here you will see the main parameters:

• 🔋 Charge level (in percent and millivolts).
• 🔌 power supply (USB, charger).
• 📊 Temperature (normal: 25-40)°C on charging, up to 45°C under load).
• ⚡ Voltage (optimum: 3.7–4.2V Li-Po batteries).

⚠️ Warning: This menu doesn't have battery wear data, only current state. 3.5V at 100% charge or temperature exceeding 50°C in simple, this is a sign of critical wear or malfunction.

💡

If the menu doesn’t open, try entering the combination through Google’s Dial (install it from the Play Market if removed).

2.Use of the AccuBattery application (without root)

AccuBattery is one of the most accurate applications for battery monitoring, analyzing charging/discharge cycles and calculating the actual battery capacity compared to the factory. For the Redmi Note 9 Pro (with a battery of 5020 mAh), the app will show how much mAh is available.

How to use:

1. Install AccuBattery from Play Market.
2. Charge your phone to 100% and wait for the calibration notification.
3. Use your smartphone as usual for 2-3 days (the app collects data).
4. Go to the Health tab to see the percentage of wear and tear.

What do indicators mean?

• 📉 Capacity: if the value is below 4000 mAh - the battery is severely worn out.
• 🔄 Charging cycles: more than 500 cycles - a reason to think about replacing.
• ⚡ Charging speed: If it falls below 1500mA, check the cable or port.

💡

AccuBattery shows real wear, not theoretical wear, and if the app captures a capacity of 4,200 mAh at a factory 5020, the battery has lost ~16% of capacity, and it should be replaced soon.

3. Checking through ADB (for advanced users)

If you want the most accurate data directly from the system, use ADB (Android Debug Bridge), which requires connecting your smartphone to your PC, but gives you access to hidden battery parameters, including the number of charging cycles and real capacity.

Instructions:

1. Enable Developer Mode on Redmi Note 9 Pro: Settings → About Phone → MIUI Version (click 7 times)

In the commands output, look for the following parameters:

• 📋 Capacity: Current capacity in %.
• 🔋 charge_counter: the number of mAh passed through the battery (compare with the factory value) 5020).
• 🔄 cycle_count: number of full charge cycles.
• ⚡ Voltage: current voltage.

🔹 Example of inference:

charge_counter: 3800 (wear ~24%)


cycle_count: 312




voltage: 3850 mV

⚠️ Attention: If cycle_count exceed 600, charge_counter below 3500 — Also check the difference between capacity (in %) and the actual level of charge in the status bar: if it exceeds 10%, calibration.

4. Diagnostics through MIUI Diagnostics (Hidden Xiaomi utility)

Xiaomi is building a hidden iron diagnostic tool called MIUI Diagnostics into MIUI, which lets you test the battery, screen, cameras and other components. For the Redmi Note 9 Pro, this tool is available through a secret code.

How to start:

1. Open the phone and type in: ##6484##

The utility will show you:

• 🔋 Battery status: Good, Normal or Bad.
• ⚡ Real-time voltage.
• 📊 Temperature (compare with normal: up to 40)°C).

🔹 Transcription of results:

5. Battery calibration: when and how to do

If your Redmi Note 9 Pro suddenly shuts down at 20-30% charge or shows an incorrect percentage, the problem may be in desynchronizing the battery controller.

Step-by-step:

⚠️ Attention: Calibration doesn't restore battery capacity! It only corrects charge display errors. If after calibration the phone still discharges quickly, the problem is the battery's physical wear and tear.

🔹 Signs that calibration is needed:

• 📱 The smartphone turns off at 15-30% charge.
• 🔋 The percentage of charge "jumps" (for example, from 50% to 20% per second).
• ⚡ After charging to 100%, the phone shows 80-90%.

💡

To speed up the discharge during calibration, turn on maximum brightness, Wi-Fi/Bluetooth and run a resource-intensive application (for example, a game or a performance test).

6.When to change the battery: signs of critical wear

Even if the diagnosis shows wear and tear of 20-25%, it is not always necessary to replace immediately.

🚨 Alert signals:

• 🔋 The phone discharges in 3-4 hours in standby mode (when worn out). >30%).
• ⚡ Charging takes more than 3 hours (norm for Redmi Note 9 Pro: 1.5-2 hours).
• 🔥 Battery heats up to 50°C+ loadless.
• 💥 The phone is swollen (check: put on a flat surface and spin - if it sways, the battery is swollen!).

📊 Comparative table of wear:

🔹 Replacement board:

The original battery for the Redmi Note 9 Pro has an article MBJ4064 (5020 mAh).The cost in Xiaomi service centers: ~1500-2000 rubles (with work). Alternatively, high-quality analogues from Baseus or Remax (from 800 rubles).

FAQ: Frequent questions about the Redmi Note battery 9 Pro