How to check the battery capacity on Xiaomi: from MIUI to the engineering menu

Owners of Xiaomi, Redmi and POCO smartphones often face the question: how to find out the real capacity of the battery, especially if the phone has been in use for several years? the manufacturer specifies a nominal capacity (for example, 5000 mAh), but over time it decreases due to natural wear. In this article, we will analyze all the available methods, from built-in MIUI tools to hidden engineering menus and third-party utilities.

It's important to understand that battery capacity and health are different concepts: capacity is measured in milliamp hours (mAh) and shows how much battery power a battery can store, and battery health (e.g., 85% of its original) reflects wear and tear, and we'll focus on accurate methods of measuring capacity, rather than rough estimates through applications like AccuBattery.

Spoiler: The most reliable way is to use ADB or an engineering menu, but it will require a computer, and if you want a quick result without additional devices, the built-in MIUI tools or apps from Google Play will do, and you can choose the method depending on your model and level of training.

1. Check capacity through MIUI settings (the easiest way)

Modern versions of MIUI (starting with MIUI 12) contain a built-in battery diagnostic tool that doesn't show the exact capacity in mAh, but shows the percentage of wear that can be used to calculate the current capacity.

1. Open Settings → Battery and Performance → Battery status.
2. Click on the gear icon (⚙️) top-right.
3. Select the Battery Diagnostics item (on some models – Battery Check).
4. Wait for the analysis to be completed (usually 10–30 seconds).

The system will show the percentage of wear, for example, "Battery condition: 88%". If the original capacity of your Xiaomi was 5000 mAh, then the current capacity will be approximately 4400 mAhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh (5000 × 0.88). Note that this method gives approximate data and may not work on older models (up to the previous model). 2019 year-end).

⚠️ Warning: Some firmware has hidden the "Battery Diagnostics" item. If it's not available, try updating it. MIUI Up to the latest version or use alternative methods from this article.

2.Use of the engineering menu (#4636##)

The hidden engineering menu provides more detailed information about the battery, including voltage, temperature and current capacity, which works on most Xiaomi devices, but requires caution — don’t change other settings on the menu to keep the phone running.

Instructions:

1. Open the Phone app and enter the combination: ##4636##.
2. In the menu that opens, select Battery Information (or Battery Information).
3. Pay attention to the line Level (charge level in %) and Health (state).
4. For the exact capacity, look at the Charge counter (if any) -- it shows the current charge in microcoulombs (μAh). To translate into mAh, divide the value by 1000.

Example: if the Charge counter shows 3.8 million, the current capacity at 100% charge is 3800 mAh. Compare this value with the nominal capacity of your model (listed on the box or in the characteristics), the difference will show the degree of wear.

Precise verification via ADB (for advanced users)

The ADB (Android Debug Bridge) tool provides the most accurate data on battery capacity, including factory and current capacity, and requires a computer with Xiaomi drivers installed and USB debugging enabled.

Step-by-step:

1. Download and install Google’s Platform Tools.
2. Enable USB Debugging in the Developer Settings (how to enable: Settings → About Phone → MIUI version – press 7 times, then go back to Additional → For Developers).
3. Connect your phone to your PC and type in the command line: adb shell dumpsys battery
4. Find the lines: charge counter: X capacity: Y where X is the current charge in μAh (divided by 1000 for mAh), and Y is the percentage of charge.

To get the maximum capacity (not the current charge), use the command:

adb shell cat /sys/class/power_supply/battery/charge_full

This command will output a value in μAh — divide it by 1000 to get mAh. For example, if the result is 4.5 million, the real battery capacity is 4500 mAh.

⚠️ Note: Some Xiaomi models (especially custom firmware) may have different paths to the file. If the command doesn't work, try: adb shell cat /sys/class/power_supply/battery/capacity Check all files in the directory. /sys/class/power_supply/battery/.

4.Applications for checking battery capacity

If you don't want to mess around with ADB or the engineering menu, you can use third-party apps. They're not always accurate, but they give you a rough idea of the battery status.

• 🔋 AccuBattery — shows battery health as a percentage and estimates capacity based on charging cycles.
• 📊 CPU-Z — Battery displays voltage, temperature and charge level, but does not show capacity directly.
• 🛠️ Battery Guru – analyzes battery wear and predicts the remaining resource. POCO.
• 📱 AIDA64 — in the Battery section shows the factory capacity and current charge, but does not always correctly read the data on the MIUI.

Important: applications can't physically measure battery capacity -- they only estimate it from indirect data (voltage, discharge time, etc.) -- for accurate results, it's better to use ADB or an engineering menu.

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If you use AccuBattery, reset the stats after installation and complete 2-3 full charge cycles (0–100%) to improve the accuracy of the capacity estimate.

Verification through test mode (for Redmi and POCO models)

Some Redmi and POCO smartphones have a hidden test mode that displays detailed battery information, a technique that doesn’t work on all devices, but could be useful for 2020-2023 models.

How to enter the test mode:

1. Turn off the phone.
2. Press and hold the Volume Up + Power buttons until the MI logo appears.
3. When the menu appears, select the language (usually English) and go to the Battery Test or Battery Info section.
4. Here you will see the Battery Capacity and Battery Health options.

On some models (e.g. Redmi Note 10 Pro), the test mode shows real capacity per mAh, not the percentage of wear. If this method did not work, try another method from the article.

6. Physical check (disassembly of the phone)

If software methods fail, you can physically inspect the battery, which is only suitable for advanced users, because it requires disassembly of the device and violates the warranty. The battery usually shows its rated capacity (for example, 4500mAh), but not its current state.

What you'll need:

• 🔧 Set of screwdrivers (star, cross).
• 🧲 Screen removal suction cup (optional).
• 📸 Hair dryer or plastic blade to disengage the body.
• 🔋 Multimeter (to check the voltage, optionally).

Algorithm of action:

1. Turn off the phone and remove it. SIM-map.
2. Heat the edges of the screen with a hair dryer (temperature not higher than 60°C) to soften the glue.
3. Carefully tuck the screen with a plastic spatula, starting at the bottom edge.
4. Disconnect the battery plume (usually under protective film).
5. The battery itself will be labeled with a label, such as HB436542ECW 4500mAh 3.85V.

⚠️ Warning: Disassembling your phone will void warranty and may damage the plumes or screen. If you're unsure of your skills, contact your service center. Also remember that bloated batteries are dangerous to remove on your own - they can ignite!

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Physical testing gives you accurate rated capacity, but it doesn't show current wear, and to assess battery health, it's best to combine this with software tests.

7. Contact the Xiaomi Service Center

If you want 100% accurate diagnostics using professional equipment, contact the official Xiaomi service center, where they use special testers that measure the capacity of the battery under load and give a detailed report.

What will be offered to you in the service:

• 🔍 Diagnostics of the battery on a special stand (cost: 300-800) ₽).
• 📊 Printing a report with current capacity, voltage and internal resistance.
• 🔧 Battery replacement (if the wear exceeds 30-40%).

Advantages of this method:

• ✅ Maximum accuracy of measurements.
• ✅ Guarantee for work performed.
• ✅ The ability to replace the battery immediately, if it has run out of resources.

Disadvantages:

• ❌ Paid service (even diagnostics).
• ❌ It takes time (usually 1-2 days).

The addresses of official Xiaomi service centers in Russia can be found on the website mi.com/ru/service. Before visiting, check by phone if they provide a battery diagnostic service without having to replace it.

FAQ: Frequent questions about Xiaomi battery capacity check