How to accurately check the residual battery capacity on Xiaomi: from the engineering menu to ADB

A smartphone battery is like a human heart: it wears out over time, loses capacity and keeps the charge worse. If your Xiaomi runs out in half a day, turns off at 20-30% or suddenly “sanks” from 50% to 1%, the problem is most likely a degraded battery. But how do you know its real residual capacity — not the one that the system shows, but the actual one, taking into account wear?

In this article, you will find 5 proven ways, from simple (via apps) to advanced (ADB commands and engineering menus), we will analyze what parameters are important (battery capacity, cycle count, voltage), how to interpret them correctly and what to do if the wear has exceeded 50%, and also unique data on Xiaomi models from 2020-2026: which batteries “live” longer and which fail in 1.5 years.

1.Why Xiaomi’s standard “charge percentage” is lying

When you look at the status bar battery icon, you see the charge estimate, not the actual data. MIUI (like any Android) calculates the percentages based on:

• 📉 Voltage: The lower it is, the lower the percentage it shows, but the voltage depends on the temperature, the load, and even the age of the battery.
• 🔄 Calibrations – if the battery has not been discharged to zero for a long time, the controller can show 100% when the real capacity is 85%.
• ⚡ Power saving algorithms in the new Xiaomi (for example, Redmi Note 12 or Xiaomi) POCO F5) The system artificially “inflates” the percentages so that the user does not panic.

Example: your Xiaomi 11T shows 30% but suddenly shuts down, which means that the actual battery capacity is below the shutdown threshold (usually 3.2-3.4 V), although the controller has not yet updated the data, which often happens when the battery is worn out (more than 60%) or after replacing the battery without calibration.

⚠️ Warning: If the phone turns off at 15 to 30 percent charge, it's not always the battery's fault. Possible causes: power controller failure, damaged charging connector or motherboard malfunction. Check capacity in the ways below -- if the wear is less than 30 percent, the problem is different.

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

The engineering menu is a hidden Android section that displays real data from the battery controller and works on all Xiaomi (except some models for China with blocked access).

How to open it:

1. Open the Phone app.
2. Enter the combination: ##4636### (on some firmwares it may not work – see the alternative below).
3. Select Battery Information (Battery Information).

What parameters are important:

If #4636### doesn’t work, try an alternative method:

1. Install the Activity Launcher app from Google Play.


2. Open it and find it in the list of "Testing" or "Engineering Mode".




3. Launch an activity called BatteryInfo.

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If you don't have Health data in the engineering menu, it doesn't mean that the battery is working, and your Xiaomi model may not support output, so use Methods 3 or 4 (ADB).

Method 2: Applications for diagnostics (AccuBattery, CPU-Z)

If the engineering menu is unavailable or the data is scarce, third-party utilities will come to the rescue, analyzing charging cycles, discharging speeds, and even predicting residual capacity.

Top.-3 apps:

• 🔋 AccuBattery shows real capacity per mAh, number of charging cycles and wear in %. Works without root, but for accurate data you need to use the phone 2-3 days.
• 📊 CPU-Z — Battery displays voltage, temperature and state (Health) minus: does not show capacity in mAh.
• 🛠️ AIDA64 — Provides the most detailed information, including battery technology (Li-Ion/Li-Pol) Design capacity (stated by the manufacturer).

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

Charge your phone to 100% and disconnect from the network |Install AccuBattery and allow all requests |Use your phone as normal 1–2 days |View Health – there will be real capacity |Compare with passport capacity (e.g., 5000 mAh for Redmi Note 11)

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Example: if AccuBattery shows 3800 mAh instead of the declared 5000 mAh, battery wear is 24% (3800 / 5000 × 100), which is the norm for a battery age of 1.5-2 years.

⚠️ Note: Apps like AccuBattery give estimates, and their accuracy depends on the calibration of the battery. If you recently changed the battery or reset, wait for 3-5 full charge/discharge cycles before checking.

Redmi Note 10/11/12|POCO F3/F4/F5|Xiaomi 11/12/13 series|Redmi 9/10 series|Other-->

4. Method 3: ADB-Teams for Advanced Users

If you want the most accurate data right from the battery controller, use ADB (Android Debug Bridge) – a method that works for all Xiaomis, but requires a PC connection.

What you need:

• 🖥️ Computer with Windows/Linux/macOS
• 🔌 Cable USB (preferably original)
• 🛠️ Established ADB and Fastboot
• 📱 Included Debugging by USB on the phone (Settings) → The phone. → Version. MIUI → 7 times to press to unlock the developer settings)

Commands to check the battery:

adb shell


dumpsys battery

In the answer, look for the lines:

• Capacity: X is the current charge in % (similar to the engineering menu).
• Voltage: X is the voltage in microvolts (divide by 1000 to get volts).
• Li-ion or Li-polymer is a type of battery.
• health: 2 — condition (2 = GOOD, 3 = OVERHEAT, 4 = DEAD).

To get real capacity in mAh use:

adb shell


cat /sys/class/power_supply/battery/charge_full_design




cat /sys/class/power_supply/battery/charge_full

Where: charge_full_design — factory-capacity, charge_full — current maximum capacity.

Example of output for Xiaomi 12 Pro:

charge_full_design: 4500000 (4500 mAh)


charge_full: 3600000 (3600 mAh)

Wear: 20% (3600/4500×100).

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ADB shows data directly from the battery controller, so it's more accurate than applications, but on some MIUI firmware (especially Chinese), access to capacity files can be blocked.

5. Method 4: Codes for USSD and hidden menus Xiaomi

Xiaomi (like other manufacturers) hides additional diagnostic menus that can be opened with special codes. They do not work on all models, but it is worth a try.

List of codes in operation:

If the code didn’t work, try adding # at the end (e.g. #4636##*#). On newer models (Xiaomi 13, Redmi Note 12), many codes are locked, in which case use ADB or apps.

Method 5: Physical inspection (multimeter and disassembly)

If software methods don't give a clear answer, you can measure the battery capacity physically using a multimeter and a load resistor, which requires disassembling the phone and is only suitable for advanced users.

What you need:

• 🔧 A set of screwdrivers (for Xiaomi you usually need a set of screwdrivers) T3 or T5).
• 📊 Multimeter with current measurement function (up to) 3A).
• 🔋 Resistor at 10-20 ohms (to create a load).
• ⏱️ Time-measuring phone or stopwatch.

How to measure capacity:

1. Turn off your phone and remove the battery (most Xiaomi has it glued on – be careful!).
2. Connect the multimeter in current measurement mode (10A) sequentially with the resistor to the battery contacts.
3. Take a look at the time it takes for the voltage to drop from 4.2 V to 3.0 V (full discharge).
4. Calculate the capacity according to the formula: Capacity (mAh) = Current (MA) × Time (hours). For example, if the current is 500 mA and the discharge time is 6 hours, the capacity = 3,000 mAh.

⚠️ Warning: Disassembling the phone takes away the warranty and can damage the plumes or battery. If you are not sure about your skills, contact the service center. Also, do not discharge the battery below 2.8V - this may make it inoperable.

Battery wear rates: when it's time to change the battery

Any lithium-ion (Li-Ion) or lithium-polymer (Li-Pol) battery degrades over time. Here are the average wear and tear rates for Xiaomi:

• 📅 6-12 months: wear 5-15% (normal for active use).
• 📅 1.5–2 years: wear and tear of 20–35% (may require replacement).
• 📅 2.5+ 40-60% wear (the battery holds a charge of 2-4 hours).

When is the time to change the battery:

• 🔋 Residual container <60% from the factory (for example, less than the 3000 mAh battery 5000 mAhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh).
• ⚡ The phone discharges at 1% per minute in idle (no load).
• 🔌 Does not hold a charge for more than 2-3 hours with moderate use.
• 💥 Battery bloating (seen over raised screen or body).

Comparative table of wear on Xiaomi models (data from 2026):

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If the battery wears more than 40%, it will be cheaper to replace it than to repair the phone after a sudden shutdown (which can damage the file system or motherboard).

8 How to extend the life of Xiaomi battery: 5 rules

Even if your battery is already worn out, these tips will help slow down the degradation:

• 🔌 Avoid full discharge: keep the charge in the range of 20-80%. Full cycle (0-100%) reduces the life of 10-15%.
• 🌡️ Control the temperature: Do not use your phone while charging (heating above 40)°C accelerates wear by 2 times).
• ⚡ Use a “smart” charger: in MIUI There is an optimised charging function (Settings) → Battery that stops the charge by 80%.
• 🔄 Calibrate the battery once every 3 months: discharge the phone before turning off, then charge to 100% without interruptions.
• 🛠️ Update the firmware: in new versions MIUI Optimized energy consumption (e.g., in the MIUI 14 Added Extreme Battery Saver Mode).

If you plan to store your phone without using a spare phone, charge it up to 50% and turn it off. Storage at 0% or 100% leads to irreversible loss of capacity.

FAQ: Frequent questions about Xiaomi's residual capacity