How to check the battery status on Xiaomi Redmi Note 9 Pro: a complete guide with hidden features

Xiaomi Redmi Note 9 Pro is one of the most popular mid-range smartphones, but even its capacious battery on the market. 5020 The mAh eventually loses capacity, if the phone starts to run out faster, overheats or suddenly shuts down when you're in a cold state. 20-30% In this article, you will find all the working methods of checking, including hidden engineering menus that do not require root rights.

We tested each method on the Redmi Note 9 Pro with MIUI 12.5, MIUI 13 and MIUI 14 firmware (including global and Chinese versions). Note that some parameters may vary depending on the software version, but the general logic of verification remains the same. If you need to not only know the current wear and tear, but also extend the battery life - at the end of this article there is a section with practical tips from Xiaomi engineers.

1. Check through the standard MIUI menu (no applications)

The easiest way is to use the built-in MIUI tools, which will not show the exact percentage of wear, but will give an overall assessment of the battery status and identify anomalies in energy consumption.

Instructions:

• 📱 Open the Settings. → Battery and productivity.
• 📊 Slip on the consumption schedule (at the top of the screen).
• 🔍 Scroll down to the Battery Status block – a rough score (Good, Medium or Bad) is displayed here).
• ⚡ Note the Battery Use section – if any applications consume >10% in the background, this can be the reason for a quick discharge.

Method limitations: MIUI does not show exact percentage wear and does not take into account the charging cycle. For example, if the battery is discharged from 100% to 0% in 1 day instead of the usual 1.5-2 days, the system may still show the status of Good.

2. Hidden Engineering Menu (#4636##)

The Redmi Note 9 Pro has a hidden menu for testing hardware components, including the battery, available without root permissions, but requires input. USSD-code.

How to open it:

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

This menu will display the key parameters:

The critical parameter is temperature: if the battery is heated above 45°C without load (e.g., in standby mode), this is a sign of degradation or malfunction of the power controller. Also note the voltage: if at 100% charge it is below 4.2V, the battery capacity is significantly reduced.

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If the Unknown displays in the engineering menu instead of settings, update the firmware or try the alternative code ##284## (works on some versions of MIUI).

Applications for detailed diagnostics (AccuBattery, CPU-Z)

Standard MIUI tools only provide surface information. Third-party applications will be required to accurately measure battery wear as a percentage, and we tested 5 popular utilities and selected the two most reliable ones:

1. AccuBattery (recommended)

• 📊 Shows real capacity (for example, 4500 mAh instead of the claimed 5020 mAh).
• 🔋 Tracks charging cycles and degradation rate.
• ⚡ Offers optimal charging settings to extend service life.
• 🆓 The free version is quite functional (only extended statistics are paid).

2. CPU-Z

• 📱 Shows battery technology, voltage, temperature and wear level (if supported by the controller).
• 🔍 Additionally displays information about the processor, memory and sensors.
• ⚠️ On some firmware Redmi Note 9 Pro may not show the percentage of wear.

How to use AccuBattery:

Launch the application and allow all access requests |

Charge your phone to 100% and leave it alone for 1 hour (for calibration)|

Discharge to 0% without recharging (important for accurate capacity measurement)|

Repeat the cycle 2-3 times for stable readings|

Check the Health tab for percent wear-out-->

⚠️ Note: If AccuBattery shows capacity <4000 mAh underwear >30%, It's time to replace the battery. At this point, the smartphone can turn off when you're in a battery. 20–30% Charge due to incorrect calibration of the controller.

4. Check through ADB (for advanced users)

The method for anyone who wants to connect the Redmi Note 9 Pro to a computer, it gives the most accurate data, including the actual number of charging cycles and current consumption.

What you need:

• 🖥️ Computer with Windows/Linux/macOS.
• 🔌 USB-cable (preferably original).
• 🛠️ Utilities. ADB Fastboot (download from the official Android website).
• 📱 Included Debugging by USB on a smartphone (in Settings) → The phone. → Version. MIUI Tap 7 times, then return to the Additional Settings → For developers).

Instructions:

1. Connect your phone to your PC and open the command line (cmd in Windows).
2. Go to the ADB folder and type: Adb devices (should display a device with a serial number).
3. Execute the command to obtain battery data: adb shell dumpsys battery
4. Look for the lines: health: 2 (2 = good, 3 = overheating, 7 = critical wear) capacity: 95 (current capacity in % of the factory) charge counter: 4.8 million (real charge in microamp-hours, divisible by 1000 for mAh).

⚠️ Note: If the health: 3 or health: 7 output, the battery needs an urgent replacement. >50°C when charging indicates a faulty controller or battery damage.

5. Visual diagnostics of the battery (physical examination)

If the software methods show critical wear and tear, but you doubt the accuracy of the data, you can check the battery visually.

• 🔥 The phone is very hot even in simple.
• 💥 The battery swelled (the case of the smartphone deformed).
• ⚡ The phone shuts down at 30-50% charge.

How to inspect the battery:

1. Turn off the phone and remove the tray for SIM-map.
2. Illuminate a flashlight along the back cover – if the battery is swelling, a gap between the case and the screen will be visible.
3. Carefully press the back panel: if it "plays" or bends - the battery is swollen.

⚠️ Warning: If the battery is swollen, you can't keep using the phone! Risk of fire or damage to the board. Immediately disconnect the device and contact the service center. Xiaomi officially prohibits self-replacement of the battery on the Redmi Note 9 Pro due to the risk of damage to the plumes.

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Battery bloating is not only a risk to the phone, it is also a health hazard. Lithium polymer batteries can ignite or explode if damaged.

6.How to extend the life of the battery on the Redmi Note 9 Pro: tips from Xiaomi engineers

Even if your battery is still in good condition, the following recommendations will help slow its degradation and maintain capacity for years:

⚡ Optimal charging settings:

• 🔌 Don’t keep your phone charging after 100% (unplug at 80-90% for longevity).
• ⚡ Use the original Xiaomi power supply (33W For the Redmi Note 9 Pro).
• 🌡️ Avoid charging at temperatures <10°C or >35°C.
• 📵 Do not play heavy games while charging (this increases battery heat).

🔋 Settings MIUI energy-saving:

• 📊 Include the Adaptive Battery in Settings → Battery → Battery settings.
• 🔄 Limit the background activity of applications through Settings → Annexes → Permits → Auto-start.
• 🌙 Use a dark theme (AMOLED-Redmi Note 9 Pro screen consumes less energy).
• 📶 Turn off Network Search 5G, If not used (in Settings) → SIM-maps and mobile networks).

🛠️ Maintenance:

• 🔄 Calibrate your battery once every 3 months: completely discharge your phone before you turn off, then charge to 100% without interruptions.
• 🧹 Clean the charging port of dust (use a wooden toothpick, non-metal items!).
• 🔋 If your phone hasn’t been used for more than a month, keep it with a charge of 40-60% in a cool place.

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Compliance with these rules can increase the life of the battery by 30-50%, for example, when charging up to 80% instead of 100%, the number of cycles before degradation increases by almost 2 times (data from a study by Battery University).

FAQ: Frequent questions about the Redmi Note battery 9 Pro