Smartphone owners Samsung often encounter a situation when the device begins to discharge faster than usual, or suddenly turns off with 10-15% charge remaining. This is a clear signal that physical capacity the battery has deteriorated during operation. Unlike some brands that hide this information deep in the system, the South Korean giant provides users with several tools for self-diagnosis. However, the standard settings menu does not always show a specific percentage number, which causes confusion among inexperienced users.
To accurately assess the health of your Li-Ion or Li-Poly energy storage device, you must use a combination of built-in engineering codes, system utilities and third-party specialized software Understanding the real state of the battery allows you to make a timely decision on replacement, avoiding sudden shutdowns at a critical moment. There is an opinion that data is required to obtain data, but in most modern models with a shell, this is not the case. Let's look at all the available methods from the simplest to the more complex. root access, but in most modern models with a shell One UI this is wrong. Let's look at all the available methods from the simplest to the more complex.
Using secret USSD codes for diagnostics
The fastest way to access the hidden diagnostic menu is to enter a special combination of characters in the Phone application. This method works on the vast majority of devices Samsung Galaxy, regardless of the year of manufacture. You need to open the standard dialer and enter the sequence *#0228#. After entering the last character, the screen will automatically switch to Battery Statusmode. The current voltage, charge level and battery status are displayed here.
However, it is worth noting that in new firmware versions Android 11, 12 and 13 the company Samsung has limited access to some parameters in this menu for security reasons. If after entering the code you see a button Quick Start, it is not recommended to press it unless absolutely necessary, as this may cause a short-term drop in the charge level on the screen (this is a software reset of the controller, and not a real discharge). More informative for checking the capacity is the code *#9900#, which opens the menu SysDump.
In the menu SysDump you need to scroll down the list and find the item Battery Info. Clicking on it will display a detailed table with technical data. Look for the line Battery Status or Level. Although it rarely states a direct percentage of wear (e.g. "85%"), you can see the estimated capacity or condition status. If the status field indicates Good, then the controller does not record critical errors.
⚠️ Attention: Do not press the button
DumporCopy to SDin the engineering menu if you do not know what it is for. This will create a huge system log file, which will take up space in the internal memory and can slow down the device.
Unfortunately, standard engineering codes do not always show the “percentage of health” figure in a form understandable to the average person. They rather confirm the serviceability of the power controller. To obtain exactly the percentage of capacity degradation relative to the factory values, it is better to use the following methods.
Analysis through the “Device Maintenance” menu
Starting with the shell One UI 3.0, the company Samsung has introduced a more friendly interface for monitoring the condition of components. This method does not require entering codes and is available to every user through standard settings. Follow the path Settings → Device maintenance → Diagnostics. In the list of tests that opens, select Battery status (or Battery Status).
The system will conduct a quick test and display the result in the form of a status: “Good”, “Bad” or “Required” replacement." This is a simplified assessment that does not give exact percentages, but clearly signals critical wear. If the system writes “Good”, this means that the remaining capacity is still sufficient for stable operation, even if you feel that the phone is living less. Algorithms system monitoring. data-i="72">If the diagnostic status of the battery is “Good”, but the phone discharges in 2 hours, the problem may not be due to wear and tear, but to background processes or a “dead” power controller on the board. take into account the number of charging cycles and the current voltage.
If the diagnostic status of the battery is “Good”, but the phone is discharged in 2 hours, the problem may not be wear and tear, but rather background processes or a “dead” power controller on the board.
For a more in-depth analysis, there is a function in the same section Battery usage logHere you can see which applications have consumed the most energy over the past day or week. is not associated with battery degradation, but with the incorrect operation of a particular softwarewhich wakes up the processor in idle mode. Checking this log helps to weed out software problems from hardware ones.
It is worth considering that the menu interface may differ slightly on different devices. models such as Galaxy S21, A52 or Note 20. The path to diagnostics remains the same, but the names of the items may vary depending on the regional firmware. If there is no “Diagnostics” item, try updating the software to the latest version, since this function was added gradually.
Accurate calculation through third-party applications
When the built-in tools are not enough, applications come to the rescue from the store Google Play. The most authoritative tool in this niche is AccuBattery. Unlike simple indicators, this application does not show data instantly. It works on the principle of accumulating statistics. After installation, you need to use the phone as usual for several days, periodically connecting it to charging.
The principle of operation is based on an analysis of the current entering the battery. the nominal capacity of your model (for example, 4500 mAh for Galaxy S20 FE) and compares it with the real amount of energy that the battery can take per cycle. After 3-5 charging cycles, the calculated percentage will appear in the “Health” tab. For example, if the nominal capacity is 4000 mAh, and the application records the real capacity of 3200 mAh, then the wear will be 20%, and the health will be 20%. 80%.
- 🔋 AccuBattery —the market leader, shows the real capacity in mAh and the percentage of health, has a user-friendly interface.
- ⚡ Battery Guru —an alternative with similar functionality, works well on older Samsung models.
- 📊 CPU-Z —more focused on the processor, but in the “Battery” tab shows the current status and manufacturing technology.
- 🛠 Ampere —useful for measuring charging and discharging current, helps identify problems with the cable or power supply.
It is important to understand that not a single application has direct access to the chemical composition of the battery. Therefore, an error of 3-5% is the norm. To obtain the most accurate data, experts recommend calibrating: discharge the phone before turning it off, charge it until it turns off. 100% without turning it off, and then reboot.
☑️ Preparing for the battery test
Checking via ADB and computer
For advanced users who do not trust third-party applications and want to get “raw” data from the system, there is a debugging method via ADB (Android Debug Bridge). This method allows you to request a file from the system batterystats.bin or get a dump of the battery status directly from the controller. You will need a computer, a USB cable and USB debugging enabled on your smartphone.
Connect your phone to the PC, open the command line and enter the command:
adb shell dumpsys batterystatsThe output will be huge, so it is better to filter the required data with the command:
adb shell dumpsys batterystats | findstr "estimated"(for Windows) or
adb shell dumpsys batterystats | grep "estimated"(for macOS/Linux).
In the received data, look for parameters Current charge and Design capacity. By comparing these values, you can calculate the percentage of remaining capacity. Also, the command adb shell cat /sys/class/power_supply/battery/capacity will show the current charge level, and .../battery/charge_counter the current charge in mAh. This method is the most accurate, since it takes data directly from the system core, bypassing interface add-ons. data-i="116">⚠️ Attention: To work with ADB, you must install the Samsung USB Driver on your computer. Without them, the PC will not see the device in debugging mode, and commands will not be executed.
⚠️ Attention: To work with ADB, you must install Samsung USB Drivers on your computer. Without them, the PC will not see the device in debug mode, and commands will not be executed.
Physical signs of battery wear
Numbers are numbers, but sometimes the battery condition is visible to the naked eye or felt tactilely. The chemical aging processes of lithium-ion cells are accompanied by the release of gases. If you notice that the back cover of the smartphone has begun to come off, the screen has risen or the case has become deformed, this is a critical sign. In this case, no apps are needed: the battery must be replaced immediately. battery swelling. In this case, no apps are needed: the battery must be replaced immediately.
Another sign is unstable behavior of the charge percentage. For example, the phone shows 40%, then suddenly drops to 15% or turns off at 20%, and after turning on again shows 50%. This suggests that power controller cannot correctly calculate the voltage due to the degradation of chemical cells. The voltage sags under load faster than the algorithm calculates.
| Symptom | Probable cause | Action |
|---|---|---|
| The phone turns off at 15-20% | High cell wear (loss of capacity) | Battery replacement or calibration |
| The back cover has come off | Battery swelling (gassing) | Urgent replacement (dangerous!) |
| Fast discharge in standby mode | Current leakage or software failure | Checking applications, resetting settings |
| Heating during charging | Controller malfunction or wear | Diagnostics in the service |
It is also worth paying attention to the charging speed. If your Samsung enabled Super Fast Charging used to hit 50% in 20 minutes but now takes an hour to warm up and charge, this may indicate that the battery can no longer accept high current due to internal resistance. The system automatically reduces the charging power to prevent overheating.
The myth of freezing the battery
On the Internet it is often advised to put the battery in the freezer to restore capacity. It is ABSOLUTELY IMPOSSIBLE to do this. Condensation inside the element will cause a short circuit and irreversible damage to the chemistry.
How to extend the life of a new battery
After replacing the battery or purchasing a new smartphone, it is important to properly operate the device to slow down the degradation process. The main enemy of lithium batteries is extreme states of charge. Constantly holding the battery at 100% or discharging it at 0% creates maximum voltage on the cells, accelerating their aging.
In the settings Samsung there is a useful function Battery protection. It allows you to limit the maximum charge level to 85% or 80%. Activating this option significantly extends the battery life, especially if the phone is often charged (for example, at night or in the office). It is better to charge the phone more often, but in small portions, maintaining the level in the range from 20% to 80%.
Temperature conditions also play a key role. Do not use the phone intensively (games, navigation) while fast charging. This causes overheating, which irreversibly reduces the capacity. If your phone is hot to the touch, let it cool before connecting it to the network. Use original cables and power supplies, as low-quality accessories may supply unstable voltage.
⚠️ Attention: The menu interface and function names may change with One UI updates. If you do not find the "Battery Protection" item, check the "Battery and Performance" section or use the search in settings.
The optimal mode for long battery life is charging in the range of 20-80% and avoiding overheating of the device above 40 degrees Celsius.
Frequently asked questions (FAQ)
Is it true that the first time the phone needs to be charged for 12 hours?
No, this is a myth left over from the days of nickel-cadmium batteries. Modern Li-Ion batteries do not have a “memory effect”. They can be charged at any time, and the first charge is no different from subsequent ones. It is enough to charge up to 100% in the usual way.
Why does AccuBattery show a different percentage of health every day?
The application calculates data based on the current charging cycle. If you interrupted charging at 60% or used the phone while charging, the calculation may not be accurate. For a stable result, you need at least 5-10 full cycles with charging up to 100% without active actions.
Is it possible to replace a Samsung battery yourself?
Theoretically yes, but modern models Galaxy S i Note have glass backs covers glued with durable sealant. When opening there is a high risk of breaking the glass or damaging the cables. It is not recommended to do this without special equipment (separator, hair dryer, suction cups).
Does calibration reset actual battery wear?
No. Calibration (adb shell dumpsys batterystats --reset or complete discharge) only synchronizes the display of percentages on the screen with the actual voltage. It does not restore chemical capacity. If the battery is physically worn out, only replacement will help.
Does fast charging 25W/45W affect wear?
Yes, high currents generate more heat, which accelerates degradation. However, power controllers Samsung are able to regulate the current when overheating. To maximize resource conservation, it is better to use conventional chargers (5V/2A), if speed is not critical.