The battery is the “weakest” component of any smartphone. Even flagship models lose up to 30–40% of their original capacity after 2–3 years, and budget devices can “degrade” even faster. But how can you tell if the battery is really worn out? After all, slow charging, sudden shutdowns at 10–15%, or overheating can indicate both software failures and hardware problems.

In this article we will analyze all available methods for checking battery wear on Android —from standard tools in the settings to hidden engineering menus and ADB commands. You will learn what indicators are considered normal, how to distinguish real wear from calibration errors, and what to do if the battery capacity drops too quickly. Instructions are relevant for devices on Android 10–14including smartphones Samsung, Xiaomi, Realme, Oppo, Google Pixel and other brands.

Important: some methods require root access or connecting to a PC. If you are not ready for such manipulations, use the first three methods from our list. They work on any Android smartphone without additional apps.

1. Checking wear through Android settings (without applications)

Many manufacturers add built-in battery diagnostic tools to the firmware. They do not always show the exact percentage of wear, but they help assess the overall condition of the battery. Let's look at where to look for this data on popular brands.

On Samsung Galaxy (One UI 5.0 and later):

  • 📱 Open Settings → Device care → Battery.
  • 📊 Tap on the three dots in the upper right corner and select Advanced.
  • 🔍 Scroll down to the block Battery status —the rating (“Good”, “Average”, “Bad”) or the percentage of wear can be displayed here.

On Xiaomi/Redmi/Poco (MIUI 13–14):

  • ⚙️ Go to Settings → Battery and performance → Battery status.
  • 📉 If the section is missing, try entering the query “battery status».
  • 🔋 On some models (for example, Xiaomi 12T) this shows real capacity in mAh and the percentage of the original value.

On Google Pixel (Android 13–14):

  • 🔄 Go to Settings → Battery → Battery Settings → Battery Status.
  • 📱 The system will show approximate wear (for example, “Capacity reduced by 10%”).
⚠️ Attention: On some smartphones (especially budget ones), built-in diagnostics may be absent or show deliberately inaccurate data. In this case, proceed to the following methods.
📊 How often do you check the battery condition?
Once a month
Once every six months
Only when problems arise
Never

2. Hidden engineering menus: how to find the real capacity through USSD codes

Manufacturers hide engineering menus from users, where you can see exact battery dataincluding voltage, temperature and actual capacity. They can be accessed through special codes entered in the Phone application.

The most common codes for different brands:

Brand Code What shows
Samsung ##4636## Testing menu, tab Battery information (charge level, temperature, voltage)
Xiaomi/Redmi ##6484## or ##64663## Section MBAT TEST with data on capacity (in mAh) and charging cycles
Huawei/Honor ##2846579## ProjectMenu → Background settings → Battery (detailed statistics)
Realme/Oppo ##36446337## Information about the battery, including Design Capacity (factory capacity) and Full Charge Capacity (current)

After entering the code, you will be taken to the engineering menu. Look for sections with names Battery, Power or MBAT. Pay attention to two key parameters:

  • 🔋 Design Capacity —factory capacity (for example, 5000 mAh).
  • 📉 Full Charge Capacity —current maximum capacity (for example, 4200 mAh).

To calculate wear, use the formula:

(Design Capacity - Full Charge Capacity) / Design Capacity × 100%

Example: if the factory capacity is 5000 mAh, and the current one is 4000 mAh, the wear will be 20%.

⚠️ Attention: Not all codes work on new models (for example, Samsung Galaxy S23 or Xiaomi 14). If the code does not work, try alternative methods.
What to do if the engineering menu does not open?

On some smartphones (especially with custom firmware), engineering codes may be blocked. In this case:

1. Try entering the code through the Google Phone application, rather than the standard one.

2. Install the application MTK Engineering Mode (for devices on a MediaTek chip) or Qualcomm EngineerMode (for Snapdragon).

3. Connect to your PC and use ADB (method No. 4 in this article).

3. Diagnostic applications: top 5 utilities with accurate data

If the built-in tools do not show wear, third-party applications will come to the rescue. We tested dozens of utilities and selected those that provide the most accurate data without the need for root access.

The best applications for checking the battery:

  • 📊 AccuBattery - analyzes charging cycles, shows real capacity and wear. Works on all brands, but requires multiple charging cycles for accurate data.
  • 🔋 Battery Guru - Displays voltage, temperature and approximate wear. Supports widgets for quick monitoring.
  • 🛠️ CPU-Z — in the section Battery shows the current capacity, charge level and health status (Health).
  • 📈 3C Battery Monitor — professional tool with discharge graphs and detailed statistics. Suitable for advanced users.
  • 🔍 DevCheck — in section Hardware → Battery shows the factory and current capacity, as well as the number of charging cycles.

How to use AccuBattery (the most accurate application):

  1. Download and install the application from Google Play.
  2. Charge your phone before 100% and wait for the “Charging complete” notification.
  3. Open AccuBattery and go to the Health tab.
  4. After 3-5 charging cycles, the application will show the exact percentage of wear.

Important: Applications without root access can show approximate data. For 100% accuracy, access to system files is required (method No. 5).

Charge the phone to 100%

Install one of the diagnostic applications

Disable battery optimization for the selected application

Carry out 2-3 full charge-discharge cycles-->

4. Checking via ADB: a method for advanced users

If you need maximum accurate data, but do not have root access, use ADB (Android Debug Bridge). This method works on any Android smartphone and does not require unlocking the bootloader.

What you will need:

  • 🖥️ A computer with installed drivers ADB (you can download from the official Android website).
  • 📱 Enabled USB debugging on the smartphone (Settings → About phone → Number assembly — tap 7 times, then return to Settings → System → For developers → USB debugging).
  • 🔌 USB cable (preferably original).

Step-by-step guide:

  1. Connect your phone to the PC and confirm permission to debugging.
  2. Open the command line (Windows) or terminal (macOS/Linux) in the folder with ADB.
  3. Enter the command: 
    adb shell dumpsys battery
  4. Find the lines in the output: 
    capacity: X

    charge_counter: Y

    where Y —current capacity in microwatt-hours (divide by 1000 to get mAh).

  5. Compare with the factory capacity (indicated on the battery label or in the model specifications).

Example output for Samsung Galaxy A52:

capacity: 87

charge_counter: 15000000

This means that the current capacity is 15,000 mAh / 1000 = 1500 mAh (with a factory capacity of 5000 mAh, wear will be 70%).

⚠️ Attention: On some smartphones (for example Huawei or Xiaomi with MIUI 14+) ADB commands may be limited. In this case, use an alternative command: 
adb shell cat /sys/class/power_supply/battery/capacity
💡

If ADB does not recognize the device, try reinstalling the drivers or using a different USB cable. Often the problem lies in non-original wires with damaged contacts.

5. Root access: how to find out wear with maximum accuracy

If you have root access, you can get full battery dataincluding the number of charging cycles, real voltage and even wear history. This method is suitable for enthusiasts who are prepared for risks (loss of warranty, possible system failures).

Instructions for devices with root:

  1. Install a file manager with root access (for example, Root Explorer or FX File Explorer).
  2. Go to the folder /sys/class/power_supply/battery/.
  3. Open the files:
    • capacity — current charge percentage.
    • charge_full or charge_full_design —factory capacity.
    • cycle_count —number of complete charging cycles.
    • voltage_now —current voltage.
  • Compare charge_full (current capacity) with charge_full_design (factory).

    • Example: if charge_full_design = 5000, and charge_full = 3800, the wear will be 24%.

    You can also use applications with root access:

    • 📊 Battery Charge Limit — allows you to limit the charge to 80% to extend service life.
    • 🔧 Battery Calibration — resets calibration data (useful in case of charge display failures).
    • 📈 BetterBatteryStats — detailed analysis of energy consumption by process.
    ⚠️ Attention: Incorrect use of root access can lead to data loss or device failure. Before experiments, make a backup copy due to TWRP or Titanium Backup.
    💡

    Root access provides the most accurate data, but the risks outweigh the benefits for most users. If you are not confident in your skills, use methods without root (method No. 1–4).

    6. Battery wear rates: when is it time to change the battery

    Even if you find out the exact wear percentage, how do you know if it is critical? We have collected data from manufacturers and independent tests to determine threshold values replacement battery thresholds

    Wear percentage Battery condition Symptoms Recommendations
    0–10% Excellent No visible problems, the phone holds its charge like new. Continue to use, monitor temperatures.
    10–25% Good Slight reduction operating time (by 10–15%). Limit the charge to 80%, avoid overheating.
    25–40% Satisfactory The phone discharges 20–30% faster, charge surges are possible. Get ready for replacement within a year. Avoid complete discharge.
    40–60% Bad The operating time has been reduced by 2 times, the phone turns off at 20–30%. It is recommended to replace the battery. Risk of sudden shutdown.
    60%+ Critical The battery is swollen, the phone overheats, holds a charge for 1–2 hours. Immediate replacement! Further use is dangerous.

    Additional signs that it is time to change the battery:

    • 🔥 Phone gets very hot when charging or under load.
    • 📵 Sudden shutdowns at 10–20% charge (even after calibration).
    • 🔌 Slow charging (for example, from 0% to 100% in 4+ hours).
    • 📏 Visible deformation of the case (swelling of the battery).

    Critical information: If the battery is swollen, immediately turn off the phone and do not use it until the battery is replaced. Lithium batteries in this condition may ignite.

    7. Common mistakes when checking wear and how to avoid them

    Many users receive inaccurate data due to errors. Let's look at the most common of them and ways to avoid them.

    Mistake 1: Trusting data immediately after buying a phone

    New batteries may show 1-3% wear due to inaccurate calibration. Give the battery 5-10 charge cyclesbefore jumping to conclusions.

    Error 2: Using apps without calibration

    Apps like AccuBattery require at least 3 full cycles (from 0% to 100%) for accurate data. Charge your phone without interruptions.

    Error 3: Compare capacity at different temperatures

    A cold battery will show a lower capacity, and an overheated battery will show a larger capacity. Check wear at room temperature (20–25°C).

    Error 4: Ignore calibration

    If the phone shows 100%, but turns off at 30%, the problem is incorrect calibration. Follow the procedure:

    1. Discharge the phone until automatic shutdown.
    2. Charge to 100% without interruptions (do not turn off cable!).
    3. Repeat 2-3 times.

    Error 5: Confusing “charge level” and “capacity”

    Applications often show Battery Level (current charge) instead of Battery Capacity (maximum capacity). Look for parameters with words Full Charge Capacity or Design Capacity.

    💡

    If the problem persists after calibration, try resetting your phone to factory settings. Sometimes battery failures are caused by software errors rather than physical wear and tear.

    8. How to extend the life of a battery: 7 rules from engineers

    Even if wear has already reached 20-30%, following simple rules will help slow down degradation and extend the battery life by 1-2 years.

    Tips from specialists:

    • 🔌 Avoid full discharge. Lithium batteries “do not like” 0% and 100%. The optimal range is 20–80%.
    • 🌡️ Control the temperature. Do not leave your phone in the sun or near heat sources. Ideal temperature - 10–35°C.
    • 🔄 Use smart charging. On Samsung i Xiaomi enable the function Optimized charging (limit the charge to 80% at night).
    • 📵 Do not play while charging. Simultaneous charging and high load (games, videos) accelerate wear.
    • 🔋 Use original chargers. Cheap cables and power supplies can damage the battery controller.
    • ⚡ Avoid fast charging unnecessarily. If you're not in a hurry, charge at 5W–10W instead of 30W+.
    • 📱 Update the software. Manufacturers optimize energy consumption in new firmware versions.

    If you follow these rules, the battery will last 30–50% longer. For example, with careful use, the battery loses only 10% of capacity in 2 years, and not 20–30%, as with intensive use. Google Pixel 6 loses only 10% of capacity in 2 years, and not 20–30%, as with intensive use.

    ⚠️ Attention: On some smartphones (for example, OnePlus or Realme) Optimized charging is disabled by default. Enable it manually in the battery settings.

    FAQ: Answers to frequently asked questions

    Is it possible to restore the battery capacity?

    No, It is impossible to restore a worn out lithium battery. All “magic” apps and chargers that promise “resuscitation” are a hoax. The only way to return the original capacity is replacing the battery.

    However, you can slow down further degradationfollowing the advice from section No. 8.

    Why does the phone show 100% charge, but quickly discharges?

    This is the problem incorrect calibration. The battery controller “thinks” that 100% = 4000 mAh, although the real capacity is already 3000 mAh. Solution:

    1. Perform full discharge-charge (3 cycles).
    2. Use the application Battery Calibration (requires root).
    3. Reset your phone to factory settings.

    If that doesn’t help, the battery is physically worn out.

    How much does it cost to replace the battery in a service center?

    The cost depends on the model and type batteries:

    • Budget smartphones (Redmi, Samsung A-series) - 1 500–3 000 ₽.
    • Flagships (Galaxy S23, iPhone 14) — 4 000–8 000 ₽.
    • Complicated repair (glued body, like a Google Pixel 6) — up to 10,000 ₽.

    Tip: Official service centers charge more, but give a guarantee of 6-12 months. Unofficial workshops can use non-original batteries.

    Is it possible to use a phone with a swollen one? battery?

    Absolutely not! A swollen battery is:

    • 💥 Risk fire or explosion.
    • 📵 Damage to the screen and motherboard.
    • ⚡ Short circuit that can damage the phone.

    If you notice swelling (the case is “spread out”, the screen has risen) — immediately disconnect the device and take it to the service.

    How often should you check the battery condition?

    Recommended frequency:

    • 📱 New phones (up to 1 year) - once every 6 months.
    • 📉 Smartphones 1–2 years old - once every 3 months.
    • ⚠️ Devices older than 2 years - once a month.

    Also check the battery if symptoms appear:

    • Sudden shutdowns.
    • Extreme heating when charging.
    • Reduced operating time by 30% or more.