The battery is the most vulnerable component of a smartphone, which degrades even with proper use. After 2-3 years of active use, its actual capacity can be reduced by 30-50%, which leads to sudden shutdowns, slow charging and overheating. But how to check how many percent of the original capacity is left? Manufacturers rarely provide this information in standard settings, and data on “battery health” in the menu Settings → Battery is often missing or distorted.

In this article you will find 7 working methods - from simple codes and applications to hidden engineering menus and ADB commands. We will look at how to find the actual battery wear on Samsung, Xiaomi, Google Pixel and other devices, and also explain why the indicators may differ in different methods. Important: some methods require root access or unlocking the bootloaderwhich may void the warranty.

1. Standard Android settings: where to look for battery data

Starting from Android 9 Pie, Google has added basic battery monitoring tools to the system, but their functionality varies greatly by manufacturer. On “pure” Android (for example Google Pixel or Motorola) the path is as follows:

  1. Open Settings → Battery.
  2. Tap on the ⋮ (three dots) icon in the upper right corner and select Battery parameters or Battery status.
  3. Look for items like Capacity, Battery health or Cycle count (number of charging cycles).

On Samsung (One UI) and Xiaomi (MIUI) this data is often hidden. For example, in Samsung Galaxy s Android 13+ you can only see condition assessment ("Good", "Average", "Bad"), but not the exact numbers. And Xiaomi Redmi/POCO sometimes the percentage of wear is displayed, but only after 100+ charging cycles.

⚠️ Attention: Manufacturers may artificially lower wear indicators in standard settings in order to “improve” the perception of the device. For accurate data, use alternative methods.
📊 How often do you check the battery condition?
Once a month
Only when problems start
Never checked
I use special applications

2. Codes for checking the battery: a quick way without applications

The simplest method is to use service USSD codes. They work on most devices, but not all manufacturers support them. Try these combinations:

  • 📱 ##4636## —universal Android testing menu. Go to the tab Battery information (Battery information). Displayed here charge level, temperature, voltage, but not always the actual capacity.
  • 🔋 ##3644## —an alternative code for some models Samsung and LG. Shows detailed battery information, including Battery capacity (if supported).
  • 📊 *#0228# - works on Samsung Galaxy (except new models with One UI 5+). Shows current charge/discharge current i voltage, but not capacity.

If nothing happens after entering the code, then your manufacturer has blocked this method. In this case, proceed to the next method.

Why don’t codes work on new smartphones?

Manufacturers are gradually abandoning USSD codes due to security risks. For example, Samsung removed support for most codes in One UI 4.0+, and Xiaomi limited their work in MIUI 13+.

3. Applications for battery diagnostics: top 5 tools

If standard methods do not produce results, install one of the specialized applications. They analyze data from the battery controller and show actual wear and tear. Important: some apps require root access for accurate indicators.

Application Accuracy Do you need Root? Features
AccuBattery ⭐⭐⭐⭐ ❌ No Shows real capacitywear, temperature and discharge rate. Works on 90% of devices.
Battery Guru ⭐⭐⭐ ❌ No Monitors charging cycles and predicts service life. Suitable for Samsung and Xiaomi.
CPU-Z ⭐⭐ ❌ No Shows only current charge and voltage, but not capacity.
3C Battery Monitor ⭐⭐⭐⭐⭐ ✅ Yes The most accurate application with support battery calibration and detailed statistics.
AIDA64 ⭐⭐⭐ ❌ No Shows Design Capacity (factory capacity) and Full Charge Capacity (current).

For maximum accuracy, use AccuBattery or 3C Battery Monitor. The first is suitable for most users, the second is for advanced users who are ready to get root. Please note: Once installed, the app needs 2-3 full charge cyclesto collect reliable data.

💡

If the app shows 80% capacity or below, consider replacing the battery. At 70% or less, the battery is considered very worn out and may turn off at 30–40% charge.

4. Engineering menu: hidden battery data

Each smartphone has engineering menu (Engineering Mode), where low-level hardware data, including the battery, is stored. Access to it varies depending on the manufacturer:

  • 📱 Samsung: Enter #0011# or #9900#. In the menu Sys Dump look for the section Battery.
  • 🔋 Xiaomi/Redmi/POCO: Use the code ##4636##, then go to Battery information. On some models it works ##284##.
  • 🤖 Google Pixel and "pure" Android: Code ##4636## → Battery history (connection to a PC is required for a detailed log).
  • 📱 Huawei/Honor: Enter ##2846579##, then select Background settings → Battery status.

In the engineering menu, look for parameters:

  • Battery Capacity —current capacity in mAh.
  • Design Capacity —factory capacity.
  • Cycle Count —number of complete charging cycles.
  • Voltage —voltage (normally 3.7–4.2V).

⚠️ Attention: Do not change parameters in the engineering menu if you do not know their purpose! This may lead to battery damage or void the warranty.

Charge the phone to at least 50%|Back up your data|Do not change unknown parameters|Record factory values for comparison-->

5. ADB commands: advanced diagnostics without root

If the previous methods did not work, try ADB (Android Debug Bridge) a debugging tool that allows you to get data directly from the battery controller. You will need:

  1. A computer with ADB drivers installed.
  2. Enabled USB Debugging in the developer settings (Settings → About phone → Build number - tap 7 times). data-i="163">USB debugging
  3. USB cable (preferably original).

Connect the phone to the PC and execute in the command line:

adb shell

dumpsys battery

B in the output, look for the lines:

  • capacity: X —current charge in percentage.
  • voltage: X —voltage.
  • technology: Li-ion —battery type.
  • charge_counter: X — actual capacity in μAh (divide by 1000 to get mAh).

For more detailed information, use:

adb shell dumpsys batterystats --charged
💡

Value charge_counter in ADB - the most accurate of all methods without root. It shows the real charge that the battery can give, and not the “cosmetic” percentage from the interface.

6. Hardware testers: professional approach

If you need 100% accurate data (for example, to sell a phone or warranty repair), use hardware testers. These devices connect to the battery contacts and measure its parameters directly. Popular models:

  • 🔌 YR1035+ —a tester for Li-ion/LiPo batteries with measurement of capacity, internal resistance and voltage.
  • 📊 SkyRC MC3000 —a professional analyzer with support for charge/discharge cycles.
  • 🔋 ZKE Tech EBC-A20 —a budget option for quick testing.

How to use:

  1. Remove the battery from the phone (on most modern smartphones this is impossible without disassembling!).
  2. Connect the battery contacts to the terminals of the tester (observe polarity!).
  3. Run the discharge test (usually a button Discharge).
  4. When finished, the tester will show the real capacity in mAh.

⚠️ Attention: Disassembling the phone will void the warranty! If you are not confident in your skills, contact the service center. Incorrect connection of the tester can lead to short circuit. data-i="192">fire or fire.

7. Assessing wear by indirect signs

If none of the methods worked, assess the condition of the battery by the behavior of the phone:

  • ⚡ Fast discharge: With a capacity below 70%, the phone may lose 1% charge per minute with active use.
  • 🔥 Overheating: If the case heats up even when simply scrolling through the social media feed, the battery has degraded.
  • 🔌 Unstable charge: For example, the phone shows 30%, and after a second turns off.
  • ⏱️ Long charging: If wear >50%, charging time may increase 2-3 times.
  • 📉 Sudden shutdowns: A typical sign that the battery controller is not calibrated correctly.

For an approximate estimate, use the formula:

Approximate wear and tear (%) = (Battery operating time now / Operating time on a new battery) × 100 - 100

For example, if the phone previously worked 10 hours, and now - 6, wear is:

(6 / 10) × 100 – 100 = -40% → 40% loss of capacity.

Why can a phone show 100% charge, but quickly discharge?

This is due to a calibration failure of the battery controller. The system “thinks” that the battery is fully charged, but in fact its actual capacity is lower. The problem is solved by completely discharging/charging or resetting through the engineering menu.

FAQ: Frequently asked questions about checking the battery

Is it possible to restore the battery capacity?

No, lithium-ion and lithium-polymer batteries they are not restored. All “restorative” applications and methods (for example, low current charging) are a myth. The only way to return the original capacity is replacing the battery.

How often do you need to calibrate the battery?

Calibration (full discharge/charge cycle) is needed once in 2–3 months if the phone shows an incorrect charge percentage. For calibration:

  1. Drain the phone until automatic shutdown.
  2. Charge to 100% without interruption (do not turn it on!).
  3. Disconnect from charging and turn on. If the percentage jumps (for example, from 100% to 80%), repeat the cycle.
Is it true that fast charging ruins the battery?

Yes, but not critical. Fast charging (Quick Charge, VOOC, Super Charge) increases the temperature of the battery, which accelerates degradation by 5–10% per year. However, modern controllers limit the current when heated. Optimal:

  • Use fast charging up to 80%, then switch to regular.
  • Do not charge the phone in the heat (for example, in the sun or while playing games).
Is it worth buying a battery on AliExpress?

Only if you are ready for risks. Cheap batteries from marketplaces often have:

  • Increased capacity (for example, instead of 4000 mAh - 2500 mAh).
  • Poor build quality (risk of swelling or leakage).
  • Lack of overheating protection.

It is better to buy original batteries from official suppliers or service centers.

How to check the battery on an iPhone?

This article is about Android, but for iPhone there is a built-in tool: go to Settings → Battery → Battery status. Apple shows maximum capacity as a percentage of the factory one. If the value is below 80%, replacement is recommended.