Previous articleSlow charging on Xiaomi: 10 reasons and how to speed up charging to 100%

You connected Xiaomi to charging, but instead of the usual “Fast Charging” or percentage on the screen, the inscription “Slow Charging”** appears on the screen? The battery charges at 1-2% per hour, and sometimes even discharges with a connected cable? This problem is familiar to many owners of Redmi, POCO and Mi smartphones – from the budget Redmi Note 10 to the flagship Xiaomi 13 Ultra. 80% of cases it can be eliminated without contacting the service.

In this article, we'll look at all the possible causes, from the commonplace contamination of the connector to the hidden firmware settings that block fast charging, how to diagnose a problem in 5 minutes, what tools you'll need to repair, and when you really need to carry your phone to the workshop, and at the end, a checklist of 7 steps for rapid check-up.

1. Problems with the cable or power adapter

The most common cause (45 percent of service centers) is a faulty cable or power supply, and even if they look whole, the inner veins could be rubbed and the contacts oxidized, especially for cheap no-name accessories that often come with Redmi budget models.

How to check:

• 🔌 Connect the original cable and adapter from another device (e.g., from the POCO F3 If the charging went faster, the problem is accessories.
• 🔍 Look at the cable on the curves (especially at the connectors), the appearance of "transparent" areas or microcracks is a signal for replacement.
• ⚡ Check the power of the adapter: for fast charging you need 18W The label on the block must contain 5V/3A, 9V/2A or 12V/1.5A.

⚠️ Note: Use of power adapters 5V/1A (For example, from the old Redmis. 4A) Automatically activates slow charging mode – the phone limits the current to 0.5-1A, so as not to damage the battery.

2.Contamination or damage to the USB-C connector

The USB-Type C connector in Xiaomi smartphones is one of the most vulnerable areas: Dust, pile from your pocket, moisture or mechanical damage (for example, after a fall) disrupt the contact between the cable plug and the socket, as a result, the phone does not recognize the connected adapter as “fast” and goes into safe mode.

Signs of a problem:

• 📱 The “Slow Charging” inscription even appears with the original cable.
• 🔄 Charging is interrupted if the cable is slightly moved.
• 💦 The screen displays a moisture warning (even if it is not there).

How to clean the connector:

1. Turn off the phone and get it out. SIM-memory-card.
2. Light up with a flashlight – if debris is visible, carefully remove it with a plastic or wooden toothpick (NOT metal!).
3. To remove oxidation, use alcohol wipes (at least 70% alcohol).
4. Dry your phone for 1-2 hours before connecting the charger.

3. Battery saving mode or background restriction is enabled

MIUI has several hidden features that can artificially limit the charging speed, most often to blame:

• 🔋 Battery Supersaving Mode (Settings) → Battery → Battery mode).
• ⚡ Optimization of charging (Settings) → Battery → Settings → Optimizing charging).
• 📱 Background Limitation for Apps (e.g. Google Play Services).

How to disable restrictions:

1. Go to Settings → Battery → Battery Mode and select Performance.
2. In Settings → Battery → Settings turn off “Optimization of Charging” and “Adaptive Charging”.
3. Check Settings → Applications → Application Management → Charging – there should be no restrictions on system processes.

💡

If the charging is still slow after optimizing is turned off, restart the phone. Some MIUI settings apply only after the reboot.

4. Failure of the battery or power controller

If the battery is worn out (capacity has fallen below 70% of its value) or the power controller is damaged, the phoneforcedly goes into slow charging mode to avoid overheating or catching fire, which is typical for devices older than 2 years or after falls/overheating.

Signs of battery wear:

• 📉 Phone's running out of power. 3-4 hourly with moderate use.
• 🔥 The body warms up even with a simple charge.
• ⚡ The percentage of charge "jumps" (for example, from 30% immediately to 15%).
• 🛑 The “Slow Charging” inscription even comes with the original adapter 33W/67W.

How to check the status of the battery:

1. Enter the code ##4636## and select Battery Information.
2. Look at the health parameter, a value of 2 or 3 is critical wear.
3. Use apps like AccuBattery (available on Google Play) for detailed diagnostics.

⚠️ Warning: If the battery is swelling (visible on a raised screen or body), immediately disconnect the phone from charging and contact the service!

5. Software failures and firmware errors

Sometimes the reason lies in MIUI — especially after updates or custom firmware installations. Errors in the core of the system can block access to fast charging functions, even if the hardware is working, and this is true for the POCO X3, Redmi Note 9 Pro and others, where users often experiment with firmware.

How to fix it:

• 🔄 Reset the settings to factory (Settings) → The phone. → Setting resets. Attention: this will delete all data!
• 📱 Flash your phone through the Mi Flash Tool (instructions for power users).
• 🔧 Reverse to the old version MIUI, If the problem occurs after the update.

For models with unlocked loader (POCO F1, Mi 9, etc.) you can try:

fastboot oem edl

Then, I can flash the phone through EDL-Mi Flash mode, which is a risky procedure, and if you make a mistake, your phone can turn into a brick».

External factors: temperature, humidity, magnetic fields

Many people don’t know that Xiaomi automatically reduces the charging speed under adverse conditions.

• 🌡️ Temperature below 0°C or higher than 45°C – Battery controller blocks fast charging.
• 💧 Increased humidity (even condensation after cold) can cause a moisture in the connector error».
• 🧲 Magnetic fields from wireless charging or powerful speakers interfere with the stable operation of the controller.

How to eliminate:

• If the phone is cold, hold it in your hands for 5-10 minutes before charging.
• Do not put your smartphone on charging near heaters or under direct sunlight.
• To eliminate condensation, use silica gel bags (go in shoe boxes) - put the phone and packages in a sealed bag for 1 hour.

💡

If the phone overheats while charging, remove the case - this will improve heat sink and can return the fast charging mode.

Hardware malfunctions: from board to controller

If all previous methods have not worked, the problem may be:

• 🔧 Damaged motherboard (for example, after falling or getting moisture).
• 🔌 Faulty power controller (microchip) PMIC).
• 📶 The snatched paths from charging connector to board.

Diagnosis at home:

• Try charging your phone wirelessly (if supported), and if the speed is normal, the connector or cable is a problem.
• Connect the phone to a PC – if it is detected and transmits data, but does not take charge, the power controller is to blame.

⚠️ Note: Motherboard repair or replacement of power controller is not recommended to do it yourself - it requires soldering equipment and experience:

• Redmi Note 10/11: 2 000–3 500 ₽
• POCO X3/X4: 2 500–4 000 ₽
• Xiaomi 12/13 series: 4 000–7 000 ₽

Checklist: 7 Steps to Eliminate Slow Charging

Before you bring your phone to the service, go through this list:

FAQ: Frequent questions about Xiaomi's slow charging