You plugged Xiaomi into charging, but the battery percentage crawls like a snail, and an hour later, the same 30% on the screen? The problem of slow charging is familiar to many owners of smartphones of this brand — from the budget Redmi Note to the flagship Xiaomi 13 Ultra. 80% of cases are not to blame for malfunctions, software failures, improper settings or worn accessories. But how to accurately determine the cause and return the previous speed?
In this article, we’ll look at all the possible causes, from the banal contamination of the connector to the hidden MIUI functions that inhibit charging, how to check the power adapter, why Quick Charge suddenly stopped working, and what to do if the phone warms up and refuses to charge faster than 5W. And also share a unique method of resetting the power controller, which is not written about even in service centers.
Don't rush to repair the machine: 9 out of 10 cases, you can solve the problem yourself in 10 to 30 minutes, starting with the most common cause - a faulty cable or power supply.
1. Checking of charger and cable
The first thing you need to do is eliminate faulty accessories. Even the original Xiaomi cable wears out over time, as the veins are rubbed, the contacts are oxidized, and the power supply loses power. How do you check?
- 🔌 Use a different power supply. Take a charge from another device (preferably with Quick Charge support). 3.0/4+) If the charging goes faster, the problem is the adapter.
- 📱 Change the cable. Even with the original power supply, the worn cable can limit the current.
- 🔍 Check the connector. USB-C. Pollution or deformation of contacts in the phone or charger leads to poor contact.: Carefully clean with alcohol and toothpick.
- 📊 Check the power. Install the AccuBattery (Android) or Ampere app, and they'll show you the actual charging current. Quick Charge's normal rate is 1.5-2.5A at 9-12V.
⚠️ Note: If you use wireless charging, remember that Xiaomi limits power to 10–20Even on supported models (Mi) 11/12/13 series, Redmi K50). It's in 2–3 wire-load.
| Symptoms. | Probable cause | Decision |
|---|---|---|
| Charging is only 5W (0.5-1A) | Faulty cable or power supply | Replace accessories with original or certified |
| The phone is periodically switched off/connected to charging | Poor contact in the USB-C connector | Clean the connector, check for deformation |
| Charging goes faster when the phone is turned off | Background or overheating | Close the applications, reduce the brightness, remove the case |
2. MIUI settings that inhibit charging
MIUI has several hidden features that can artificially limit the charging speed, most often to blame:
- 🔋 "Optimized charging" (Settings → Battery → Battery settings. This feature limits the charge to 80-90% to save battery capacity. Turn it off if you want to charge fully.
- ⚡ "Fast charging. In some firmware, it's disabled by default. Check Settings. → Additionally. → Fast charging.
- 🌡️ Overheating, battery temperature above 40°C MIUI Automatically reduces current. Make sure the phone doesn't warm up (lower brightness, close games).
- 📵 Power saving mode. Includes background restriction and reduces charging speed. → Battery → Energy saving regime.
⚠️ Note: On Xiaomi models with battery capacity 5000 mAh and higher (Redmi Note) 11/12 Pro, POCO X5) last 20% The charge may go slower – this is normal and prolongs the battery life.
Turn off "Optimized Charging" |Enable "Fast Charging" in settings |Check the battery temperature |Deactivate the power saving mode-->
If the speed has not increased after the changes in the settings, proceed to the next step - battery diagnosis.
Diagnostics of the battery: wear and calibration
Xiaomi's average battery life is 2-3 years (300-500 charge cycles), and then the capacity drops by 20 to 30 percent, and the charging speed decreases. How do you check the wear and tear?
- Install AccuBattery or CPU-Z. These apps will show the actual battery capacity and the number of charging cycles.
- Compare it to passport data. For example, if the Redmi Note 10 Pro originally had 5,020 mAh, and now it has 3,800 mAh, the battery is 25 percent worn out.
If the wear is more than 30 percent, the battery needs to be replaced, but sometimes calibration of the power controller helps.
- Discharge the phone to 0% (until it shuts down).
- Connect to the original charger and charge up to 100% without interruptions.
- Turn off power and reset via Settings → About Phone → Resetting → Reset battery settings (not available on all models).
What if the phone is 100% but it is running out?
4. Software glitches and MIUI updates
Sometimes slow charging is caused by firmware bugs, especially after updates. For example, MIUI 13-14 has had cases where the system misidentified the type of charger and limited the current to 5W.
How to fix it:
- 🔄 Restart the phone. It's banal, but it often helps, it resets background processes that could have blocked charging.
- 📲 Update. MIUI. Check for updates in Settings → The phone. → Update the system. If a new version is available, install it.
- 🧹 Clear the cache. Go to Settings. → Warehouse → Clear the cache. This will eliminate possible system process conflicts.
- 🔧 Reset the settings. If the problem occurs after the update, reset to factory settings (Settings) → Additionally. → Backup and reset) Important: pre-return the data!
⚠️ Note: On some models (POCO F3, Redmi K40) After resetting the settings, you may need to re-activate Quick Charge in the engineering menu:
##4636## → Info about battery → Enable fast charging💡
After the update MIUI The phone stopped supporting fast charging, try to roll back to the previous firmware version via the Mi Flash Tool. 4PDA in your model themes.
5. Problems with USB-C connector and power controller
If you have excluded accessories, settings and firmware, but charging is still slow - the problem may be a physical malfunction:
- 🔌 Oxidation or contamination of the connector: dust, moisture or corrosion disrupt contact. Clean the connector with isopropyl alcohol (at least 90%) and a soft brush.
- 🔧 If the connector is deformed (for example, after a fall), the contacts may not touch the plug of the cable.
- 📱 This chip controls charging and discharging the battery, and when it's damaged, the phone can only charge 5W or not recognize charging at all. It's only diagnosed at a service center.
- ⚡ Motherboard problems. In rare cases, burnt tracks or capacitors are to blame, such as after moisture or a surge in voltage.
How to temporarily get around the problem with the connector:
- Try inserting the cable at a different angle (sometimes helps with bent contacts).
- Use wireless charging (if the model supports).
- Connect the charger through USB-Hub – Sometimes it bypasses problematic contact.
💡
If the phone only charges when it's off, it's a 100% faulty power controller or connector, and self-repair is not possible, requiring soldering equipment and experience.
External factors: temperature, covers, background processes
Even a good Xiaomi can charge slowly due to external conditions.
- 🌡️ Ambient temperature: Optimal range for charging: 10-35°C. Temperatures below 0°C or higher than 40°C MIUI automatically reduces current.
- 📱 Cover or bumper: Tight covers (especially silicone ones) degrade heat sink, causing the phone to overheat and limit charging. Remove the case while charging.
- 🎮 Background processes: Games, navigation or video in 4K They load the processor, which increases the temperature and reduces the charging speed.
- 📶 Weak network signal. In areas of poor coverage, the phone spends a lot of energy searching for the network, which slows down the charging.
⚠️ Note: If you use Power Bank, make sure it supports Quick Charge or PD (Power Delivery. Cheap power banks often only issue 5V/1And even if it says otherwise on the body.
| Factor. | Impact on charging | How to eliminate |
|---|---|---|
| Temperature below 10°C | Charging is 2-3 times slower | Charge in a warm room |
| Silicone/plastic case | Overheating → Current restriction | Remove the cover or use a thin one. |
| Playing or streaming video | Increases the temperature of the CPU | Close all applications before charging |
7. When to contact the service center
If you've tried all of these, but your phone is still charging slowly, it's time to call a specialist. Here are the clear signs that you need a professional diagnosis:
- 🔋 The phone is charged only when it is off.
- ⚡ On the screen appears the message "Charger is not supported" even with the original RAM.
- 📉 The charging speed drops over time (for example, the first 10 minutes goes to 18W, then drops to 5W).
- 🔥 The phone is very warm in the area of the battery or connector.
- 🛠️ Connector. USB-C wobbles or the cable is held only at a certain angle.
The cost of repair in official Xiaomi services:
- Replacement of the connector USB-C: 1 500–3 000 ₽.
- Battery replacement: 2,000–5,000 ₽ (model-wise).
- Repair of the power controller: 3000-8000 ₽ (ration).
- Diagnosis: 500–1,000 ₽ (Frequently free if you agree to a repair).
⚠️ Warning: Don’t trust repairs to informal workshops if they offer to “switch the charging controller” for a “switch-on” 500 ₽. Often it's a scam: they just reset the settings, and the problem remains. Xiaomi's official service centers can be found on the website. mi.com/ru/service/center.