The Xiaomi Redmi Note 8, released in 2019, is still a popular device due to its balance of price and quality. However, like any lithium-ion battery, its battery will wear out over time. Owners often notice that the device starts to discharge faster, warms up or unexpectedly turns off when charged 15-20%. Understanding the real state of the battery is the first step to solving the problem.
Android doesn’t have one obvious battery health button like iOS, but Xiaomi has implemented a number of hidden tools and diagnostic menus that allow you to get accurate data about charging cycles, current voltage and temperature without installing questionable software. We’ll look at all the methods available, from standard settings to engineering menus.
It is important to understand that timely diagnosis helps avoid more serious problems, such as battery bloating or damage to the motherboard due to voltage surges. In this article, we will discuss in detail how to interpret the numbers obtained and when it is really time to think about replacing a part.
Symptoms of battery degradation Redmi Note 8
Before we get to the technical checks, it’s worth analyzing the behavior of your Redmi Note 8 in everyday use. The lithium polymer batteries installed in this model have a limited resource of recharge cycles. When this resource is exhausted, the chemical processes inside the cell become less efficient, which manifests itself in specific features.
A sharp spike in percentages is one of the surest signs of a malfunction, and if the phone shows 40% charge and suddenly turns off after a minute or drops to 10%, this indicates that the controller is out of sync and real capacity, and you should also pay attention to excessive heating of the case during charging or simple tasks, such as watching social networks.
- 📉 The smartphone is running out to 0% faster than 3-4 screen-hour.
- 🔥 The back cover warms up significantly even without running heavy games.
- ⚡ Charging occurs unevenly: quickly gaining up to 80%, and the last percentage “drips” for a very long time.
- 🚫 The device turns off in the cold when the charge is above 30%.
If you see at least two of these symptoms, the probability that the battery capacity has dropped below the critical level (70-60% of the original) is extremely high. Visual inspection is also important: if the back cover of the Redmi Note 8 began to move away or the screen slightly raised, the battery is swollen, in which case it is dangerous to use the device.
⚠️ Warning: If you notice that the smartphone body is deformed or the battery is swelling, immediately stop charging and using the device.Continuing to use may cause the display to catch fire or damage from the inside.
Checking through the CIT (Engineering Menu) Hidden Menu
The most reliable way to get information about the state of hardware on Xiaomi smartphones is through the use of the built-in CIT (Customer Integrated Test) diagnostic interface, a tool designed by engineers to test components in the factory, but also available to ordinary users, which shows the current voltage, temperature and connection status.
You will need a standard dialing interface to enter the diagnostic menu. Enter the following character combination: ##6484##. If the code is entered correctly, the screen will automatically switch to the testing menu. Find the item associated with the battery, usually called "Battery" or "Battery Indicator".
What if the code doesn't work?
Inside the menu, you'll see the technical parameters, and we're not just interested in current charge, but also in battery status, and if the system says "Good" or "Normal," it means that the controller doesn't pick up critical errors, but this menu doesn't always show the State of Health (SOH) wear rate, so more advanced diagnostics are often required.
☑️ Diagnosis through CIT menu
Analysis of usage statistics in MIUI settings
The MIUI shell on which the Redmi Note 8 is based provides some detailed power consumption statistics. Although it doesn't show chemical wear, a breakdown chart analysis can tell you if the battery is loading. Go to Settings → Battery and click on the gear icon or the Statistics button.
Here you'll see the discharge graph over the last 10 days. Notice the dramatic drops in the graph. If the line goes down smoothly, that's OK. If you see the steps where 15-20% of the charge is lost in 10 minutes, that's a sign that the actual capacity is very different from the calculated capacity. Also check the application list: if the background processes consume energy disproportionately, it's probably a software failure rather than a battery.
In the same section, you can activate Advanced Settings, make sure you include an option called Extended Time or a similar power saving feature, which will help the system to more aggressively manage background processes, which will slightly prolong the life of an aging battery, but this is just a software crutch that does not solve a physical problem.
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For a more accurate analysis of the statistics, try to discharge the phone before turning off, then charge to 100% when turned off, which will help calibrate the controller and the statistics in MIUI will become more correct.
Using third-party applications for accurate diagnosis
Since standard Xiaomi tools do not always show battery health percentage (SOH), it is advisable to use specialized software. AccuBattery is considered the most authoritative application in this field. It works on the principle of monitoring charging and discharging current, calculating the real capacity based on many cycles.
After installing AccuBattery, don’t expect instant results.The application takes time (usually 3-5 charging cycles) to accumulate data and calculate the actual capacity in mAh. For the Redmi Note 8, the standard capacity is 4000 mAh. If the application shows 2800-3000 mAh, the wear is about 25-30%, which is a reason for replacing.
| Parameter | Normal for Redmi Note 8 | Critical significance | What does it mean? |
|---|---|---|---|
| Nominal capacity | 4,000 mAh | Less than 3,000 mAh | Physical deterioration of chemistry |
| Tension at rest | 3.7 - 3.8 B | Below 3.4 B | Deep discharge of the cell |
| Temperature. | 25 - 35 °C | Above 45°C | Overheating or CZ |
| Charging cycles | 300-500 | More than 800. | Resources exhausted |
Other useful utilities include Ampere or Battery Health, which allow you to check the charging current. If when you connect a powerful power supply (for example, 18 watts, which supports the Redmi Note 8) the current remains low (less than 1000 mA), perhaps the problem is not the capacity, but the power controller or cable.
ADB Teams for Advanced Users
For those who are not afraid of the command line and have USB debugging enabled, there is a way to get data directly from system logs via Android Debug Bridge (ADB), a method that allows you to see information hidden from conventional applications, including the exact number of recharge cycles if the battery driver transmits this data.
Connect your smartphone to your computer, activate debugging mode in Settings → About Phone → MIUI version (click 7 times) and in the developer menu. Enter the command to get battery status:
adb shell dumpsys batteryThis command will display your current status, charge level, voltage and temperature, and you can use the following to get more information about health:
adb shell dumpsys batterystats --charged💡
The ADB commands give raw data from the controller, and if the health bar says 2 (Good), the system thinks the battery is in good condition, even if the battery is running less.
It is worth noting that interpreting ADB data requires technical knowledge. Voltage values can fluctuate depending on the load. For example, a value of 4200 mV means full charge, and 3600 mV - about 50%. Sharp surges in voltage under load (for example, when starting a camera) indicate high internal resistance of the battery, which is characteristic of older cells.
When a battery replacement is needed
The decision to replace the Xiaomi Redmi Note 8 battery should be based on a combination of factors. Software methods show numbers, but physical condition is more important. If the diagnosis shows wear and tear of more than 20-25% (residual capacity less than 3000-3200 mAh), comfortable use of the smartphone becomes impossible.
You also need to replace it if the battery is swelling. In the Redmi Note 8, the battery is glued to the frame, and if it is swelling, it can damage the display or plumes. In this case, do not try to puncture or compress the battery, this will lead to a fire. Carefully remove the device and contact the service.
- 🔋 Capacity wear exceeds 25% according to AccuBattery.
- 🌡️ Phone warms to 45°C+ down-to-earth.
- 📱 There is a detachment of the back cover or screen.
- 📉 Phone turns off when charged 15-20% cold.
When choosing a new battery, give preference to original components or quality analogues from well-known brands (for example, Nohon, Deji). Cheap copies from marketplaces often have a real capacity of 2-3 times less than the declared one and can be dangerous. Remember that a quality replacement will return your Redmi Note 8 to a second life.
⚠️ Warning: Self-replacement of the battery in the Redmi Note 8 requires skill, as the back cover is glass and glued around the perimeter.A mishandled opening can lead to a lid break or damage to the plume (fingerprint scanner), which is often integrated into the power button.