How to check the battery status on Xiaomi Redmi 8: a complete guide with hidden features

The Xiaomi Redmi 8, launched in 2019, features a 5,000mAh battery, one of the model’s key advantages. However, over time, even the most capacious batteries degrade: real capacity declines, battery life deteriorates, and the phone suddenly turns off at 20 to 30 percent charge. If your Redmi 8 starts to run too fast or warm up while charging, it’s time to diagnose battery status.

In this article, you will find 5 proven ways to test the battery, from built-in MIUI tools to professional applications and engineering codes. We will also look at what battery wear indicators are considered critical for the Redmi 8 (spoiler: if the capacity falls below 70% of the nominal battery requires replacement), and give tips for extending its life. All instructions are adapted to current firmware versions and do not require root rights.

1. Check the battery with hidden test code ##4636##

The fastest way to get basic battery information is to use Android’s engineering menu, which works on all Xiaomi smartphones, including the Redmi 8, and doesn’t require third-party apps to be installed.

To open the menu:

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

In this section you will see the key parameters:

🔋 Level of charge (level) – current percentage in digital form.
🔌 Power source – displays Battery (from battery) or USB/AC (when connected to charging).
🌡️ Temperature – Normal values for Redmi 8 at rest: 25–35°C. Exceeding 40°C signals overheating.
📊 Voltage – must be in the range of 3.7-4.2 V. Values below 3.5 V or above 4.3 V indicate a malfunction.

⚠️ Warning: If the battery temperature exceeds 45°C in normal use (not during games or charging), this may indicate battery bloating - immediately disconnect the phone and contact the service center!

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To save data from the engineering menu, take a screenshot of the screen – press Volume down + Power at the same time.

2. Diagnostics through MIUI Battery Care (built-in tool)

Firmware MIUI Redmi 8 includes a hidden Battery Care utility that analyzes battery status and offers optimization recommendations. MIUI 12 and newer.

How to start Battery Care:

Go to Settings → Battery and Performance.
Slap the icon. ⚙️ (Battery settings) in upper right corner.
Select Battery Health (Battery Health) status.

In this section you will see:

📉 Battery Health Assessment (Excellent to Critical).
⚡ Real capacity in mAh (for example, 4200/5000 mAh means wear on 16%).
🔄 Number of full charging cycles (norm for lithium-ion batteries up to 500 cycles).
📅 Date of first use (helps estimate battery age).

Indicator.	Normal for Redmi 8	Critical significance
Real capacity.	4500-5000 mAh	< 3,500 mAh (70% of nominal value)
Number of cycles	< 300	> 500
Temperature in plain	25–35°C	> 45°C
Autonomous time	1.5-2 days at an average load	< 10 hours

If the actual battery capacity has fallen below 3,500 mAh, it means that the battery is worn out by more than 30% and needs to be replaced. At values of 3000 mAh and below, the phone can turn off at 30-40% of the charge due to incorrect display of the level.

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

Once a month

Only when problems arise

Never checked.

I don't know how to do that.

3.Use of the AccuBattery application for detailed analysis

The third-party AccuBattery app (available on Google Play) provides the most accurate data on battery wear, including discharge charts, health scores and autonomy forecast.The app runs rootless and is compatible with Redmi 8.

How to use AccuBattery:

Install the app from Google Play.
Connect your phone to charge and wait 100% (the app will collect data about the charging speed).
Use your smartphone in normal mode to a discharge of up to 5-10%.
Go to the Health tab to view the results.

Key metrics in AccuBattery:

📊 Health score – percentage of nominal capacity (e.g. 85% means wear and tear of 15%).
⚡ Real capacity - calculated based on the analysis of charging cycles.
🔋 Autonomy forecast – how long the phone will last with current wear.
📈 Discharge graphs – help identify applications that consume too much energy.

⚠️ Note: AccuBattery only shows reliable results after 3-5 full charge-discharge cycles!

Example of interpretation of results:

🟢 90-100% battery in excellent condition.
🟡 80-89% moderate wear, autonomy decreased by 10-20%.
🔴 70-79% – heavy wear, need replacement in the next 3-6 months.
⚫ < 70% critical condition, battery can fail at any time.

Charge the phone to 100%|Turn off battery optimization for the app in the settings MIUI|Do not use ultra-fast charging.|Discharge your phone to 5% without recharging|Repeat the cycle 2-3 times for accuracy-->

4. Verification through ADB-Teams (for experienced users)

If you want the most accurate battery data, you can use ADB (Android Debug Bridge), which requires connecting the phone to a computer, but provides access to hidden parameters that standard tools don't show.

Instructions for checking the battery through ADB:

Install. ADB-PC drivers.
Turn on USB Debugging on Redmi 8: Go to Settings → About Phone, tap 7 times on MIUI Version, then go back to Settings → Additional → For Developers and activate debugging.
Connect your phone to your PC and open the command line (Windows) or terminal (macOS/Linux).
Enter the command to check the status of the battery: adb shell dumpsy battery

In the conclusion of the command, pay attention to the following parameters:

Level is the current level of charge.
Voltage is the voltage in microvolts (divided by 1000 to produce volts).
Temperature is a temperature in tenths of a degree (for example, 320 = 32.0°C).
Health: 2 is good, 3 is bad (replacement required), 4 is critical (the battery may fail).

Example of output for a serviceable battery:

level: 85




Voltage: 3987000 (3.987 V)




temperature: 305 (30.5°C)




health: 2

⚠️ Note: If the health setting is 4 or 7, it means that the battery controller has detected a critical malfunction, in which case continued use of the phone without replacing the battery may cause swelling or fire!

What if the ADB does not recognize the device?

If the adb device command doesn’t show your Redmi 8, follow the following steps: 1. Make sure debugging is enabled. USB. 2. Reinstall Xiaomi drivers from the official website. 3. Try another one USB-4. Enter in the command line: adb kill-server adb start-server If the problem persists, check if the antivirus is blocking the connection.

5. Visual and physical signs of battery wear

In addition to software methods, the Redmi 8 battery can be assessed by external signs.

🔥 Overheating of the case – if the phone heats up even at minimal load (for example, in standby mode), this is a sign of battery degradation.
📉 A sharp drop in charge level – for example, from 50% to 1% in a few minutes.
🔌 Slow charging – if the phone charges longer than 3 hours from the original adapter (regular for Redmi 8 – 2-2.5 hours).
💥 Battery bloating – if the phone body becomes convex and the screen begins to “step away” from the frame, immediately turn off the device!
⚡ Spontaneous shutdowns – the phone turns off at 20-30% charge due to incorrect calibration of the controller.

If you notice a battery bloating, do not try to charge it or use your phone. Lithium-ion batteries in this state can ignite. Contact a service center to replace it.

To check if the battery is swelling:

Place your phone on a flat surface (such as a table).
Easy to press the center of the back cover – if it bends or “plays”, it is a sign of bloating.
Illuminate the flashlight at the junction of the screen and the case - if a gap is visible, the battery is deformed.

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A bloated battery is not only a loss of autonomy, but also a direct safety hazard, and lithium-ion batteries in this state can explode when mechanically exposed or overheated.

6. Battery calibration: when and how to do it

If your Redmi 8 is showing an incorrect charge level (for example, jumps from 50% to 20%), the problem may be in desynchronizing the battery controller, in which case calibration will help, a procedure that resets data about charging cycles and forcibly recalculates the capacity.

How to Calibrate Your Battery on Redmi 8:

Discharge your phone to 0% (until it turns off on its own).
Connect the original charger and charge up to 100% without interruptions.
Turn off the charger and turn on the phone. If the charge level is below 100%, reconnect the charge until full charge.
Repeat the process 2-3 times.

Calibration helps in the following cases:

📉 The phone turns off at 10-20% charge.
🔄 The charge level jumps (for example, from 80% to 50%).
⚡ Quick discharge after firmware update.

⚠️ Attention: Calibration doesn't restore the actual capacity of the battery; it only adjusts the display of the charge level. If after calibration the autonomy has not improved, the problem is the physical wear of the battery.

If the calibration didn’t help, try resetting your phone to factory settings:

Go to Settings → About the phone → Reset settings.
Select Reset all settings (does not delete files) or Delete all data (complete reset).
After resetting, recalibrate the battery.

7.When it's time to change battery to Redmi 8: checklist

Replacing the battery with Redmi 8 is required in the following cases:

Autonomy has been reduced to <10 hours|The phone turns off when 20–30% charge|The battery swelled or deformed the body|Real capacity. < 3500 mAhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh|Temperature in plain > 40°C-->

Cost of battery replacement in service centers:

Type of service	Cost (rupe)	Guarantee
Official Xiaomi service	1800–2500	6–12 months
Informal service	1200–1800	3–6 months
Self-sustaining replacement	800–1200 (battery cost)	No.

When choosing a service, pay attention to:

🛠️ Battery used - the original has the marking BM47 or BM48.
🔧 Replacement method – when self-replacement is high risk of damaging plumes or display.
📄 Guarantee – official services give a guarantee of up to 1 year.

If you are replacing the battery yourself, you will need:

New battery (for example, the original BM47).
A set of T3-T5 screwdrivers and a plastic mediator for opening the case.
Thermoclei or bilateral tape to fix the new battery.

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Before replacing the battery, completely discharge the phone and turn it off, which minimizes the risk of short circuit when the plume is disconnected.

FAQ: Frequent questions about the Redmi battery 8

❓ Can I use the Redmi 8 with a worn-out battery?

If the wear is less than 30% (real capacity > 3,500 mAh), the phone can be operated, but the autonomy will be lower. If worn out > 50% (capacity < 2,500 mAh), the battery can damage the power controller, which will lead to breakage of the phone, and the risk of bloating is also high, in which case the use is dangerous.

❓ Why Redmi 8 is fast discharged after the update MIUI?

Firmware updates often reset battery optimization. To fix this: Go to Settings → Battery → Battery Optimize. Select All apps and enable optimization for everyone. Calibrate the battery (discharge to 0%, charge to 100%). If the problem persists, try resetting to factory settings.

❓ How to check the originality of the battery after replacement?

The original battery for the Redmi 8 has: BM47 or BM48 labeled on the label; holographic sticker with the Xiaomi logo; 5,000 mAh capacity (indicated on the body); a 4-pin plume (non-original often have 3 contacts); also the original battery weighs ~45 grams, while counterfeits weigh 35-40 grams.

❓ How many charging cycles can the Redmi 8 battery withstand?

The Li-ion batteries in Redmi 8 are designed for 500-600 full charge-discharge cycles. After that, the capacity drops to 70-80% of its face value. One cycle is a discharge from 100% to 0%, regardless of the number of charges. For example, if you discharged the phone from 100% to 50%, and then again to 100% and to 50%, this counts as 1 cycle.

❓ Can I use wireless charging for Redmi 8?

Redmi 8 does not support wireless charging at the hardware level. Using adapters with a receiver can lead to: overheating of the battery (temperature rises to 50 ° C and above); Accelerated degradation of capacity (loss of 20-30% in 3-6 months); damage to the power controller. If you need wireless charging, consider buying a phone with support for Qi (for example, Xiaomi 11 Lite 5G NE).