Why it’s important to know the real battery capacity of your Xiaomi
Have you noticed that the Xiaomi Redmi Note 10 Pro or POCO X3 Pro is running out twice as fast as a year ago? Or did battery life not improve after the battery change? The problem may lie in the actual battery capacity, a parameter that rarely matches the manufacturer's stated capacity. The nominal capacity (for example, 5020 mAh for the Redmi Note 11 Pro+) is the maximum that the battery could give when released from the factory. Over time, due to charging cycles, overheating or using poor-quality RAM, this figure drops.
In this article, you will learn how to check the current battery capacity on any Xiaomi, Redmi or smartphone. POCO — from budget models (Redmi) 9A) We'll take a look at the hidden engineering menus, the secret ones. USSD-codes, applications from Xiaomi and third-party utilities that will show not only the nominal value, but also the degree of wear of the battery as a percentage, which will help to decide whether it is enough to optimize charging or it is time to change the battery.
Important: Verification methods are different for smartphones on MIUI and Android One (for example, Mi A3). Also, some methods require unlocking the bootloader or root rights - we will note them separately.
Method 1: Checking with secret code ##4636##
The fastest method that works on most Xiaomi smartphones without installing additional apps. ##4636## Engineering menu is hidden in the system, but contains data on the battery, network and device usage.
How to check:
- Open the application "Phone" (keyboard set).
- Enter the combination: ##4636### - the menu will open automatically.
- Go to the tab "Battery Information".
Here you'll see:
- 🔋 Level of charge (level) - current percentage.
- 🔌 Power source: battery (from battery) or usb (from charging).
- 📊 Health status – if Good is indicated, wear is minimal.
- ⚡ Voltage – Normal for Li-Pol batteries: 3.7-4.4 V.
⚠️ Note: On some models (POCO F3, Xiaomi 12T) 4636## can be blocked. If nothing happens after you enter the code, try an alternative method.
Method limitation: This does not show the actual capacity in mAh, only general status information. For accurate data, move on to the next method.
Method 2: Security App – built-in battery test
Xiaomi has added a hidden partition to its own Security app to diagnose the battery, which works on all devices with MIUI 12 and later, including the Redmi Note 12, POCO X5 and Xiaomi 13 Lite.
Instructions:
- Open the Security app (shield icon).
- Go to the section "Optimization» → «Battery».
- Slap the icon «⚙️» (settings) in upper right corner.
- Select “Battery Health” (Battery Health)
A graph will appear on the screen with two key parameters:
- 📉 Nominal capacity – factory value (for example, 4500 mAh for Redmi Note) 11S).
- 📈 Current capacity is a real indicator taking into account wear (for example, 3800 mAh).
- 🔄 Percentage of wear – if the value exceeds 30%, the battery is recommended to be replaced.
Advantage: does not require root or third-party application rights, disadvantage: some firmware may not have a partition (e.g., on global versions of POCO M4 Pro).
☑️ Preparation for battery inspection
Method 3: AccuBattery application - detailed wear analysis
If Xiaomi’s built-in tools don’t show real capacity, use the third-party AccuBattery utility (available on Google Play).The app analyzes charging cycles and calculates the exact capacity based on data from the battery controller.
How to use:
- Install AccuBattery and provide all the permissions you request.
- Charge your phone to 100% and wait for notifications from the app.
- Go to the Health tab.
- Please note the line “Estimated capacity”.
What AccuBattery shows:
| Parameter | What does it mean? | Normal value. |
|---|---|---|
| Design capacity | The real size of the battery, taking into account wear | At least 80% of the denomination |
| Wearing | Percentage of capacity loss | Up to 20% - the norm, higher - critical |
| Temperature. | Current battery heating | 25–40°C (optimally 30–35°C) |
| Discharge speed | Consumption of mAh per hour | Depends on the model (for example, 100-300 mAh / h in standby mode) |
Important: AccuBattery needs at least 3-5 full charge cycles to accurately calculate its capacity, and the initial data may be incorrect.
💡
If AccuBattery shows a capacity of 20-30% below par, but the phone is working normally, check the battery calibration: discharge to 0%, then charge to 100% without interruption.
Method 4: MTK Engineering Menu (for smartphones powered by MediaTek processor)
Xiaomi devices on MediaTek chips (Redmi 9T, POCO M3, Redmi Note 10) have an extended engineering menu, where you can see the real battery capacity in mAh. This method requires caution - wrong actions can disrupt the smartphone.
Instructions:
- Install the MTK Engineering Mode app (available on Google Play).
- Open the app and go to the MTK Settings section.
- Select "Hardware Testing» → «Battery».
- Note the line “Battery Capacity” – here is the current capacity.
Example of data for Redmi 9A (rated 5000 mAh):
- 🔋 Battery Capacity: 4200 mAh (real capacity).
- 📉 Deviation: 16% (wear and tear).
- 🔌 Voltage: 4.35 V (current voltage).
⚠️ Warning: Do not change other options in MediaTek's engineering menu! this could cause loss IMEI or damage to the communication module. Use the menu only to view the data.
What to do if the engineering menu is not opened?
Method 5: ADB-Teams for Advanced Users
If none of the previous methods worked, you can get battery data through Android Debug Bridge (ADB), which is suitable for all Xiaomi models, but requires USB debugging and a computer enabled.
Step-by-step:
- Download Platform Tools (includes adb.exe).
- Turn on “USB Debugging” in the developer settings (Settings → About Phone → MIUI version – tap 7 times).
- Connect your smartphone to your PC and execute in the command line: adb shell cat /sys/class/power_supply/battery/capacity_level cat /sys/class/power_supply/battery/charge_full_design cat /sys/class/power_supply/battery/charge_full
Transcript of commands:
- 📊 charge_full_design — nominal capacity (factory).
- 📈 charge_full — actual capacity (current).
- 🔋 capacity_level — percentage-rate.
Example of output for Xiaomi 11T Pro:
charge_full_design: 5000
charge_full: 4100
capacity_level: 82This means that the actual battery capacity is 4100 mAh (wear and tear 18%).
💡
ADB-Teams are the most accurate way, but they require technical skills. If you're not sure what to do, use applications like AccuBattery.
How to interpret the results: when to change the battery
You got the capacity data -- what's next? Here's the criteria for making a decision.
| Percentage of wear and tear | Real capacity. | Symptoms | Recommendations |
|---|---|---|---|
| 0–10% | 90-100% of the denomination | No visible problems. | Keep using, keep track of the temperature. |
| 10–20% | 80–90% | Fast discharge during loading (games, videos) | Optimize background processes, calibrate the battery |
| 20–30% | 70–80% | The phone discharges in 4-6 hours, warms up when charging | Prepare to be replaced, avoid full discharges |
| 30%+ | Less than 70% | Turns off at 20-30%, does not hold the charge | Urgent replacement! Risk of battery bloating |
Additional signs of critical wear:
- 🔥 The smartphone is very warm even with a simple charge.
- 📵 Turns off at 15-20% charge (false indicators).
- 🔌 Charges only in a certain position (contact problems).
- 💥 Visible swelling of the body (especially in Redmi) 8/8A).
If your Xiaomi falls into the last two categories, delaying battery replacement is dangerous.Advanced Li-Pol batteries can swell and damage the screen or motherboard when worn heavily.