How to check the battery on Xiaomi Redmi Note 8 Pro: from the code *#*#4636#*#*** to stress tests

Why the Redmi Note 8 Pro Battery Needs Special Attention

Xiaomi Redmi Note 8 Pro, released in 2019, is equipped with a battery capacity of 4500 mAh with support for fast charging 18W. However, after 3-4 years of active use, even high-quality lithium-polymer batteries lose up to 30-40% of their original capacity. The problem is exacerbated by the fact that the Redmi Note 8 Pro does not have a removable battery – it requires disassembly of the case to replace it, which increases the risk of damage during unqualified repairs.

The first signs of battery wear often go unnoticed: the phone starts to run 15-20% faster than a year ago, or suddenly shuts down at 10-15% charge. In this article, we will analyze 5 reliable ways to check the status of the battery, from hidden engineering menus to professional applications, and learn how to interpret the results to understand whether it is time to change the battery or optimize the settings enough.

Important: all of the methods described below do not require root rights and are safe for the device. However, some tests (such as the CPU stress test) can temporarily raise the temperature of the smartphone - watch for heating the case!

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

The fastest way to get basic battery information is to use Android’s hidden engineering menu, which is available on all Xiaomi smartphones, including the Redmi Note 8 Pro, and does not require additional apps to be installed.

Instructions:

1. Open the Phone app.
2. Enter the combination: ##4636## (some firmware may require ##4636*#*#).
3. In the menu that appears, select 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 on the screen).
• 🔌 Power source – must be Battery (if the charger is connected, it will be USB or AC).
• 🌡️ Temperature – normal values: 25–40°C. Exceeding 45°C in normal use signals battery degradation.
• 📊 Status – Must be Good (if Unknown or Dead, the battery is critically worn out).
• ⚡ Voltage – Normal for Redmi Note 8 Pro: 3.7–4.35V. Values below 3.5V squash.

1. Make sure you enter the code without spaces or characters |2. Try the alternative combination ##4636*#*#|3. Restart your phone and try again |4. Update your MIUI firmware to the latest version-->

Critical note: the “Health” option in the Redmi Note 8 Pro’s engineering menu is often displayed as “Good” even when 20–30% wear.

Method 2: USSD codes for battery testing

In addition to the engineering menu, Xiaomi has special USSD-codes that allow you to run diagnostics on hardware components, including the battery, which are not officially documented, but are firmware-tested. MIUI 11–14.

The main codes for the Redmi Note 8 Pro:

Example of code ##6484##:

1. Enter the code in the Phone app.
2. A menu with battery settings will appear on the screen. Notice the Battery health bar, which can show the percentage of wear (e.g., 85% means the battery has lost 15% capacity).
3. If you see Normal instead of interest, then the wear is minimal (less than 10%).

Once a month|Six months|Only when the problems start.|Never checked.-->

⚠️ Attention: Some USSD-codes may not work on custom firmware or after updating MIUI. If nothing happens after entering the code, do not try more than 2 times - this can cause a failure in the communication module.

Method 3: Applications for detailed diagnostics

To more accurately assess the state of the battery, it is recommended to use specialized applications, which analyze data from the power controller and build discharge schedules, which allows you to identify hidden problems.-3 Checked utility for Redmi Note 8 Pro:

1. AccuBattery (Play Market)

• 📊 Tracks charging/discharge cycles and calculates real capacity.
• 🔋 It shows battery health in % (for example, 92% means a loss of 8% capacity).
• ⚡ Offers optimal charging settings to extend service life.

How to use: Once installed, charge your phone to 100% and discharge to 0% without connecting the charger, and the app will collect data and show the real capacity.

2. CPU Throttling Test (Play Market)

• 📉 Tests the performance of the processor with a discharged battery.
• 🔥 Identifies trottling (forced power reduction) due to a weak battery.
• 📈 Builds voltage and temperature graphs in real time.

3. AIDA64 (Play Market)

• 🛠️ Shows accurate technical data: voltage, battery technology, number of cycles.
• 📋 Save logs for comparison with reference values.
• 🔍 It works without root, but with root it gives you advanced information.

💡

If after installation AccuBattery shows a battery capacity of 3800-4000 mAh instead of the declared 4500 mAh, this means wear by 15-20%.

Comparison of applications by functionality:

Method 4: Visual Diagnostics and Physical Signs of Wear

Even without special tools, you can detect battery problems by external signs.

1. Battery bloating

• 🔍 Signs: the screen or back cover begins to "go away", the body curves.
• 🚨 Hazard: A bloated battery may rupture when heated or mechanically exposed.
• 🛠️ Action: Turn off your phone immediately and contact the service center.

2.Overheating

• 🌡️ Normal: up to 40°C under intense load (games, charging).
• ⚠️ Requires attention: heating above 45°C in plain or when charging up to 80%.
• 🔥 Critical: temperature 50°C+ — battery to be replaced.

3. Abnormal behavior when charging

• ⚡ Symptoms: the phone is charged with jerks, shows 100%, but immediately shuts down.
• 🔌 Causes: Charging controller or battery contacts damaged.
• 📉 Consequences: Risk of short circuit.

To check the swelling without disassembling the device:

1. Place your phone on a flat surface (screen up).
2. Easy press the center of the back cover – if the case “springs” or there are gaps, the battery is swollen.
3. Check if the edges of the screen stick out relative to the frame.

⚠️ Warning: If the battery starts to run out or warm up faster after the phone falls, this may indicate damage to internal contacts, in which case even diagnostic applications may show incorrect data - a physical examination in the service is required.

Method 5: Autonomy Stress Test

The most reliable way to assess the actual state of the battery is to conduct a controlled test of autonomy, which will show how long the phone will last in different use scenarios, and help compare the results with the reference values for the Redmi Note 8 Pro.

Preparation for the test:

1. Charge the phone to 100% and turn off the charger |2. Turn off Wi-Fi, mobile data and Bluetooth|3. Set the screen brightness to 50%|4. Close all background applications-->

Test scenarios:

How to interpret the results:

• 🟢 If the operating time in each scenario differs from the norm by no more than 15-20%, the battery is in good condition.
• 🟡 A deviation of 20-40% indicates average wear and tear – it’s time to optimize settings (for example, limit the background activity of applications).
• 🔴 Autonomy drop of more than 40% – critical wear, need replacement.

💡

The stress test is most accurate at ambient temperatures of 20–25°C. When tested in cold (10°C) or hot (30°C+), the results can be distorted by 10–15%.

What to do if the battery is worn out?

If the diagnostics show that the battery capacity has dropped below 70% of the original, it's time to consider replacing it.

1. Official Xiaomi service

• ✅ Pros: Original battery, 6 months warranty.
• ❌ Cons: high cost (from 3000-4500 rubles with work).
• 📍 Where to look: list of authorized service centers on mi.com.

2. Informal services

• ✅ Pros: the price is lower by 30-50% (from 1500-2500 rubles).

3. Self-substitution

• ✅ Pros: minimum cost (battery costs from 800-1500 rubles).
• ❌ Cons: Requires disassembly skills, risk of damage to plumes.
• 🛠️ What you need: a set of screwdrivers, a mediator for putting the lid on, a hair dryer for softening the glue.

Tips for extending the life of a new battery:

• 🔌 Use the original Xiaomi charger (or Quick Charge 3.0 certified).

FAQ: Frequent questions about the Redmi Note battery 8 Pro