The situation when your Xiaomi smartphone charges obscenely long, familiar to many users. Instead of the stated hour before full battery, the process can be delayed for three or four hours or even stop at a certain percentage.
The reasons for this behavior of Android devices can be found both in the banal wear of components and in software failures of the MIUI or HyperOS shell. Often the owners of flagships with support for fast charging Quick Charge or Power Delivery do not even suspect that their gadget works in normal mode due to poor-quality cable.
In this article, we will take a closer look at all the factors that can affect the rate of energy replenishment, learn how to diagnose the problem yourself, without resorting to the services of a service center, and a competent approach to diagnosis will save time and money.
Diagnostics of cable and charger
The first thing that needs your attention when it comes to charging speed is the physical condition of the cable and the power supply, and that's where the energy goes to the battery, and any losses at this point are critical. Cheap cables often can't withstand the currents needed to charge quickly, and the smartphone automatically reduces the power consumption.
Visually inspect the wire along the entire length, and if you notice bloating, clamping, or damaged insulation, it's best to dispose of it immediately, even if the cable is intact, the veins may have broken inside, causing the voltage to drop, and also check the USB plug, which should sit tightly in the socket and not stagger.
Pay special attention to the power supply. If you use non-original charging, it may simply not support Xiaomi protocols. The smartphone can charge standard 5 volts instead of 9 or 12, which increases the process time by many times.
⚠️ WARNING: Using cheap Chinese chargers without safety certificates can lead to voltage spikes, which is dangerous for your phone's power controller.
Try replacing the cable with a well-known and high-quality cable, preferably original or certified by third-party brands like Anker or Baseus. If the speed recovered after the replacement, the problem was in the wire.
Problems with the charging connector
The USB Type-C or Micro-USB connector is a mechanical element that is subjected to constant physical stress, and over time, it accumulates dust, pocket pile and small debris, and this plaque is compressed and prevents the cable plug from contacting the current tracks inside the port.
So the result is that the phone can charge, it can shut down, it can charge very slowly because of poor contact, and to test this hypothesis, you can look carefully at the port in good light, you can use another phone's flashlight, and you can see the compressed dust layer at the bottom of the connector.
For cleaning, you should not use metal objects such as needles or pins, as there is a risk of closing contacts or damaging the central tongue.
☑️ Cleaning the charging connector
Carefully, without much pressure, try to clean the garbage from the bottom of the connector. Often after such a simple procedure, the phone starts charging at the maximum speed supported by the power supply.
The Impact of Background Processes and Applications
If the physical components are fine, you should pay attention to the software part, and the background processes can consume a significant amount of power even when the screen is off, which creates a situation where the energy coming from the network is almost immediately consumed by the system, and there is almost no real accumulation in the battery.
Often, the culprits are heavy apps, social media or games that haven't been shut down correctly, and high loads can create synchronization or system updates, so to identify the culprit, go to the battery settings.
In Settings → Battery and Performance, you can see a flow chart and a list of the most voracious applications. If you see a program that you don't use but it's actively using up, you should limit it or remove it.
It's also worth checking if the quick charging feature is enabled in the software.Some versions of MIUI have a charge optimizer that can slow down the process at night to extend battery life by learning your habits.
How to turn off charge optimization?
Temperature and overheating
Lithium polymer batteries are very sensitive to temperature, and the battery management system (BMS) specifically limits the current charge if the sensors detect overheating of the device, and it's a protective mechanism that prevents bloating or fire.
If you charge a phone lying on a soft blanket, under a pillow or in the sun, the heat is not removed, and the charging speed drops, and the phone can heat up from the processor if you continue to play or watch videos while connecting to the network.
The optimum temperature for fast charging is room temperature, in the range of 15 to 25 degrees Celsius, and when you exceed this threshold, the power controller reduces the current to cool the cells.
| Condition of the telephone | Impact on charging | Recommended action |
|---|---|---|
| Cold (below 0°C) | Charging may not go at all | Warm the device to room temperature |
| Normal (15-25°C) | Maximum speed | Remove the cover for better heat sink |
| Heated (35-40°C) | Reduced charging current | Stop using, remove heat sources |
| Hot (above 45°C) | Charging stopped by the system | Turn off the phone, let it cool completely. |
To improve heat removal during charging, it is recommended to remove a dense silicone or leather case, which will allow the case to better dispense heat to the environment.
System settings and energy saving
The MIUI and HyperOS shells have flexible energy saving settings that can affect battery replenishment rates. In the "Energy Saving" mode, the system limits background activity and can reduce performance, which indirectly affects charging algorithms.
Check if you're in Super-Savings mode, and in this state, the phone is limiting functionality for survival, and the priority is not charging speed, but keeping the system running.
You should also pay attention to the settings of the screen. If you charge a phone with the display on, the brightness of the screen becomes the main consumer of energy. Decreasing brightness or using a dark theme (on AMOLED screens) will reduce the overall power consumption.
⚠️ Warning: Flight mode significantly speeds up charging, as it turns off energy-consuming communication modules (GSM, Wi-Fi, Bluetooth, but you will be unavailable for calls.
If you need to charge your phone as quickly as possible, turn on flight mode or just turn off the device. When it's off, the phone charges the fastest, since all systems except the charge controller are de-energized.
Battery wear and calibration
Over time, the capacity of a lithium-ion battery is irreversibly reduced. After 500-800 charge-discharge cycles, the battery can lose up to 20% of its original capacity. The old battery takes charge less well, and the process can seem longer and more unstable.
Sometimes the problem is not physical wear, but the desynchronization of the controller and the actual capacity. The phone can show 100% when it's actually charged 80%, or it can drop interest dramatically, and calibration helps in these cases.
Calibration is simple: discharge the phone to zero, then charge it when it's off to 100 percent, then charge it when it's off, then charge it for another hour, then turn it on. If it's below 100 percent, recharge it.
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You can use an engineering menu to check the battery status on Xiaomi ##6485## It's in the phone app. MB_06 The health of the battery will show (Good/Bad), MF_05 — residual capacity.
If the engineering menu shows bad status or the residual capacity is critically small (less than 70% of the nominal value), the software methods will not help.