How to know exactly the battery status on Xiaomi Redmi Note 8: Step-by-step instructions

Xiaomi Redmi Note 8 — One of the most popular smartphones of the middle price segment, but over time even its capacious battery on the market. 4000 The mAh starts to lose capacity. If the phone runs out too fast, it turns off when it's not. 20-30% When you're charging or overheating while charging, it's time to check the battery's status. In this article, you'll find all the working ways to diagnose a battery, including hidden engineering menus, third-party apps, and data analysis through the battery. ADB.

We're not going to limit ourselves to superficial tips like "look at the settings," but instead, you'll get unique methods that service centers use to measure battery wear, including decoding technical parameters like Cycle Count and Battery Health, and learning how to distinguish software failure from physical battery wear, which will save you on unnecessary repairs.

1. Verification through standard MIUI settings

The easiest way to get basic information about the battery is to use the built-in MIUI tools, which will not show the exact percentage of wear, but will help to identify abnormalities in the battery.

Open the Settings menu → Battery and Performance → Battery status. Here you will see:

📊 Use schedule – how fast the phone discharges in active and sleep modes.
⏱️ The screen time is when 100% less charge 4-5 clock, battery worn out.
🔋 Battery temperature - the norm up to 40°C, if above – check the charger or cable.
🔄 High-consumption apps – sometimes the problem isn’t the battery, but the background software.

Note the Battery Optimization section, where if the system constantly recommends that you turn off background processes, it's an indirect sign that the battery is not holding a charge, and you can see the energy savings recommendations that MIUI generates based on your usage analysis.

⚠️ Note: If you see a message in the Battery Status section saying “Recommended to replace the battery”, it means that the battery capacity has dropped below the current level. 70-75% In this case, further diagnosis is only needed to confirm before replacement.

📊 How often do you check the battery status on your smartphone?

Once a month

Only when the problems start.

Never checked.

I use special applications.

2. Hidden engineering codes for diagnostics

Xiaomi hides from users advanced data about the battery, but they can be obtained using service USSD-These commands work on all Redmi smartphones, including the Note 8 and Note 8 Pro.

Open the Phone app and enter the following combinations:

🔢 ##4636## – opens the Testing menu, where in the Battery Information section you can see: Level of charge (Level) Voltage (normal 3.7–4.2V) Temperature Technology (TEM) Technology, should be Li-ion)
🔢 ##6484## - Test MTK Engineer Mode (powered by MediaTek processors) Go to MTK Settings → Battery Information for detailed statistics.
🔢 ##64663## - Alternative code for checking battery status and charging history.

If nothing happens after entering the code, check:

Are there any extra symbols or spaces in the combination?
Does the code on your version of MIUI work (on some firmware, the engineering menu is blocked)?
Are there restrictions on USSD-Requests (for example, through applications to block calls).

Parameter	Normal value.	Sign of wear and tear.
Voltage (Voltage)	3.8 to 4.2 V at 100% charge	Below 3.5 V at 20% charge
Temperature (Temperature)	25–40°C when charging	Above 45°C in plain
Charge level (Level)	Corresponds to the indicator in the status bar	Sharp jumps (for example, from 50% to 20%)
Technology (Technology)	Li-ion or Li-poly	Any other meaning

💡

If the engineering menu doesn't open, try typing code through the Phone app in dial mode, not through searching in settings. On some firmware, this is the only way to work.

3. Applications for deep diagnostics

Standard MIUI tools provide limited information, and third-party utilities are better for full battery health analysis, and we tested dozens of apps and selected those that work exactly on the Redmi Note 8:

Top.-3 battery-testing:

📱 AccuBattery shows the actual capacity, number of charging cycles and wear rate. Feature: takes into account Cycle Count (normal up to 500 cycles).
🔋 Battery Guru monitors temperature, voltage and predicts the remaining life.
🛠️ AIDA64 — In the Battery section, you can see Health (percentage of wear) and Wear Level.

How to use AccuBattery (step-by-step instructions):

☑️ Diagnostics of the battery in AccuBattery

Install the app from Google PlayCharge your phone to 100% and calibrate it.Use your smartphone until it is discharged to 15%Check the Health section for wear analysis

Done: 0 / 4

After 2-3 cycles of charging / discharging, the application will show:

Real capacity (for example, 3200 mAh instead of the declared 4000 mAh).
Percentage of wear (if more than 30%, it is time to change the battery).
Discharge speed in mAh / h (normal 100-200 mAh / h in simple).

⚠️ Attention: Some applications (e.g, CPU-Z) Incorrect battery data on Xiaomi due to restrictions MIUI. Use only specialized utilities from our list.

4. Check through ADB (for advanced users)

If you want the most accurate data about the battery, including hidden parameters like charge_counter (charge-counter) or current_now (current current, use ADB (Android Debug Bridge: This method requires a PC and basic command line knowledge.

Instructions for connection:

Turn on Developer Mode on your phone: go to Settings → About Phone and click on MIUI Version 7 times.
Activate Debugging by USB in the Developer Menu.
Connect the phone to your PC, install ADB drivers and open the command line.
Enter the command: adb shell dumpsy battery

In the answer, pay attention to the following parameters:

Level: Current level of charge (0-100).
Voltage is the voltage in microvolts (divided by 1000 for volts).
Temperature is a temperature in tenths of a degree (for example, 320 = 32.0°C).
charge_counter — Number of mAhs passed through the battery for all time (reveals real wear and tear).
current_now — current current in microamps (negative value) = discharge).

To calculate the actual capacity of the battery:

Charge your phone to 100%.
Execute the command adb shell dumpsys battery and write down the value charge_counter (for example, 4000000 μAh = 4000 mAhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh).
Discharge the phone to 0% and execute the command again.
Difference between the initial and the final charge_counter — This is the real capacity of your battery.

What if the ADB does not recognize the device?

1. Check if the debugging is included USB developer-setting. 2. Install official Xiaomi drivers from the site en.miui.com/a/adb.html. 3. Try another one. USB-cable (preferably original). 4. Restart your phone and PC. 5. If you are using Windows, run the command line on behalf of the administrator.

5. Physical Diagnosis: When Replacement Is Needed

Even if software tests show that the battery is fine, physical signs may indicate a need for replacement.

🔥 Bloating – if the back cover or screen starts to “go away”, immediately disconnect the phone!
⚡ Instant shutdown – the phone is turned off when 20-30% The indicator is normal, although the indicator shows a normal level.
🔌 Slow charging - if with 0% before 100% phone charges more 3-4 (with a proper charger).
🌡️ Overheating – the battery heats up even in a simple (for example, up to 50).°C when watching video).

How to check for bloating:

Place your phone on a flat surface (such as a table).
Lightly press the center of the back cover – if it bends or “plays”, the battery is swollen.
Illuminate the flashlight from the side to the junction between the screen and the case - if a gap is visible, this is a sign of deformation.

⚠️ Warning: If the battery is swelling, don't try to charge the phone or use it any further. Lithium-ion batteries in this state can ignite. Take the device to a service center for safe disposal.

💡

If the phone turns off at 15-20% charge, but after restarting, it shows 0%, which is a sure sign that the battery controller is not calibrating the capacity correctly, and 90% of the time, replacing the battery helps.

6.How to extend the life of a battery: tips from Xiaomi engineers

Even if your battery is still in good condition, the following recommendations will help slow its wear and tear and keep the capacity for many years:

🔌 Charging: Use the original Xiaomi charger (5V/2A or 9V/2A). Do not leave your phone on charge all night long – turn off when you do it. 80-90%. Avoid fast charging (unless it is critical) as it accelerates degradation.
🌡️ Temperature: Do not use your phone in the cold (below 0)°C) or in heat (above 35)°C. Do not cover your phone while charging (e.g. with a blanket) Avoid playing games or heavy tasks while charging - this heats up the battery.
🔄 Charging cycles: Try not to discharge the phone until 0%. Optimal range — 20–80%. If you don’t use your phone for a long time, keep it charged. 40-50%.

Myths you shouldn't believe:

❌ "You need to completely discharge the phone once a month, which was true for nickel batteries, but not for lithium-ion batteries.
❌ "Fast charging spoils battery: Xiaomi’s modern controllers regulate current to minimize harm.
❌ "Charging from Power Bank harms the battery – if Power Bank is of high quality, there is no difference with the socket.

If you notice that the battery is running out faster after the MIUI update, try:

Reset the settings to factory (pre-make a backup).
Turn off automatic battery optimization in settings.
Remove unused applications that may work in the background.

FAQ: Frequent questions about the Redmi Note battery 8

🔋 What is the normal wear of the battery after 2 years of use?

For the Redmi Note 8, wear is normal to 20-25% after 2 years (assuming 1 charging cycle per day). If wear is greater than 30%, the battery should be replaced. In heavy use (games, video shooting), wear can reach 35-40% over the same period.

📉 Why your phone is running out at 10% overnight?

The reasons may be as follows: 🔄 Background processes (check in Settings) → Battery → Battery utilization). 📡 Bad network signal (the phone spends energy searching for a connection). 🔌 Battery worn out (if the phone is older) 2 years). 🤖 Viruses or malware (scan your phone with antivirus) to reduce the cost, turn off Wi-Fi/Bluetooth At night, activate Do Not Disturb and add restrictions for energy-consuming applications.

🔌 Can I use a charger from another phone?

Yes, but with reservations: ✅ Chargers with similar characteristics can be used (e.g, 5V/2A from the Redmi Note 7). ⚠️ It is not recommended to use charges with voltage higher 5V (for example, 9V/2A from POCO F1), If you have a Redmi Note 8 Does not support Quick Charge. ❌ Cheap uncertified charging is prohibited, as it can damage the power controller, with Xiaomi’s original charging or certified accessories (such as those from Anker or Baseus) being the best option).

🛠️ How much does it cost to replace the battery on the Redmi Note 8?

Cost of battery replacement in 2026: 🔧 Official Xiaomi service center: 1500-2500 rubles (with a guarantee of 6 months). 🏠 Informal workshops: 1000-1800 rubles (guarantee 1-3 months). 🛒 Self-replacement: 800-1,200 rubles (the cost of a battery on AliExpress or in Russian stores).When choosing a wizard, note: Does he use the original battery (the box should have a Xiaomi sticker) Does he give a guarantee for work (at least 3 months). Checks whether the controller is charging after replacement (sometimes it fails due to an old battery).

📱 How to Calibrate the Battery on Redmi Note 8?

Calibration helps if the phone is not displaying the percentage of charge correctly (for example, jumps from 50% to 20%).Instruction: Completely discharge the phone before turning off. Connect the original charge and charge for at least 8 hours (even if the indicator shows 100%). Turn off charging, turn off the phone and reconnect charging for 1 hour. Turn on the phone and reset the battery settings in Settings → Annexes → Application management → Three points. → Reset the application settings. If the calibration didn't work, the problem is the battery wear and tear -- you need to replace it.