Modern Xiaomi smartphones are famous for high performance and capacious batteries, but over time, even the highest quality batteries degrade. Users often notice that the device discharges faster, turns off in the cold or shows the wrong percentage of charge.
Checking the battery is not just a way to find out what’s left, but also an important safety step. A bloated or faulty battery can damage the internal components of a gadget. In this article, we’ll look at all the methods available, from simple engineering codes to deep analysis through ADB.
Unlike some competitors, the MIUI and HyperOS shells don't always give users direct access to a complete cell health report, but the hidden capabilities of the system allow for exhaustive information if you know where to look. Let's look at these methods in detail.
Use of the Engineering Menu through Codes
The fastest way to access hidden diagnostic tools is to use special tools. USSD-In Xiaomi phones, the main tool is the menu. CIT (Customer Integration Test, which is originally designed for factory engineers. To get there, open the standard Phone app and type in the code ##6484#. If the code didn't work, try the alternative ##4636##, which opens the testing menu.
Once you enter the combination, you'll see a list of tests, and we're interested in Battery or Battery Indicator, and you'll see real data from the power controller, bypassing the system interface add-ons, and you'll see the current voltage, temperature and charging status, and it's important to understand that different firmware versions may have different names, but the point remains the same.
In this menu, you can run a discharge or charge test to see how the controller behaves under load. If the voltage drops too sharply or the phone turns off at 20-30%, this is a clear sign of physical wear and tear of the cells. Also pay attention to temperature: overheating above 40 degrees at rest indicates problems.
Analysis of statistics through MIUI settings
The MIUI built-in features offer a basic but useful monitoring function. Go to Settings → Battery. Here you will see a graph of energy consumption over the past 24 hours or 10 days. This helps identify parasitic applications that plant a charge in the background, creating the illusion of a bad battery.
But for a deeper look, you need to look at usage statistics, click on the gear icon in the upper right corner of the battery screen, and you can see a detailed breakdown by application, and if you see that the Android or MIUI system process is consuming a disproportionate amount of power, there may have been a calibration failure or background process.
It's worth noting that the standard menu doesn't show recharge cycles. Owners often use third-party utilities to get this information, but even a built-in analyzer can tell if there's a problem, for example, if a phone charges to 100% in 20 minutes and discharges in an hour, this is a sign of loss of capacity.
Checking wear through ADB and PC
For those who want to get the most accurate data, including the number of recharge cycles, the best solution is to use USB debugging. This method requires connecting the smartphone to the computer and installing ADB drivers. First, you need to activate the developer mode: seven times click on the MIUI version in the About Phone section.
Then turn on USB debugging in the developer menu. Connect the device to your PC and enter a command in the command line to get the battery log.
adb shell dumpsys batteryThis command will display the current status, charge level, health status, and technology, but to see the cycle count, root access or specific commands for a particular processor (Snapdragon/MediaTek) is often required.
adb shell cat /sys/class/power_supply/battery/cycle_countIf the path to the file is different, it can be found by studying the directory structure. /sys/class/power_supply/. The resulting number of cycles should be compared to factory standards. 80% post-container 500-800 cycle.
☑️ Preparation for diagnosis through ADB
Third-party diagnostic applications
If you don't want to mess with the command line, Google Play's specialized apps will come to the rescue, and AccuBattery is the leader in this niche, and it works by comparing the declared capacity to the actual amount of energy taken during charging.
To get an accurate result, the app needs to work for a few days, it collects statistics and gives you a total battery health percentage (Battery Health). Other popular utilities, such as Ampere or Battery Guru, also show the current of charge and discharge in real time, which is useful for detecting problems with the controller.
⚠️ Attention: Apps can't magically learn the actual wear of chemistry in one second; they need time to collect statistics; don't trust programs that promise to "restore" the battery software -- it's physically impossible.
They also allow you to track your self-discharge rate, so leave your phone overnight with monitoring running, and in the morning you'll see how much percent was lost in downtime, and it's normal to have 3-5% in 8 hours of sleep.
Visual examination and physical signs
There's no substitute for a careful visual inspection, and if the software tests show normal, but the phone is acting strangely, the problem may be physical, and you should look at the back cover first, and if it starts to move or swell, the battery needs to be replaced immediately.
Also, the signal of malfunction can be uneven heating of the case.Touch the smartphone while charging: if one part (usually the lower third or center) is hotter than the rest, this indicates an internal short circuit or degradation of cells in this area.
| Sign. | Probable cause | Action. |
|---|---|---|
| Bloating of the hull | Gas generation inside the cell | Urgent replacement |
| Shutdown by 20-30% | Voltage subsidence under load | Calibration or substitution |
| High heat. | Internal resistance has increased | Diagnostics of the controller |
| Long charge. | Wear or bad cable | Checking cable and port |
Another method is the sway test, and if you put your phone on a flat surface, you try to spin it, and if it spins like a top, it means that the battery inside is swelling and lifting the body, which is a critical sign that requires immediate intervention, because it's dangerous to keep it running.
Battery calibration: myths and reality
Often users confuse physical wear with controller desynchronization. If the phone shows 15% and shuts down abruptly, it may have miscalibrated. The controller forgets where 0% and 100% are, and full calibration helps in these cases.
The process is to discharge the phone until it's completely turned off, then, without turning it on, charge it. 100%, Don't put the cable away yet. 1-2 And then you can boot the system, and that'll help the controller rewrite the table of voltage values.
It's important not to overuse full discharges. Deep discharge is bad for modern Li-Pol batteries. Calibrate no more than once every 3-6 months if you see a clear failure in the percentage indication.