Xiaomi phone is slowly charging: what to do if it was fast before?

Your Xiaomi smartphone used to get 50% charge in half an hour, and now it barely gets to 20% in the same period of time? Slow charging is one of the most annoying problems, especially when the phone is needed “right now.” The reasons for this behavior can be more than a dozen, from the banal contamination of the connector to hidden firmware failures. In this article, we will not just list the possible culprits, but give step-by-step instructions with the features of Xiaomi, Redmi and POCO devices.

It's important to understand that if the phone charges fast and then it starts to brake abruptly, it's almost never about the battery's natural wear (it's gradually showing up), it's probably about software failure, damaged hardware, or external factors like a non-original cable, and we've put together all the working methods, from simple (cleaning the connector) to advanced (resetting the power controller), so you can get back to speed without going to the service.

1. Checking of charger and cable

Start with the obvious: 90% of slow-charging problems are due to a faulty or unoriginal charger. Even if you use Xiaomi's "native" power supply, its contacts could oxidize and its cable could rub.

• 🔌 Connect another charger (preferably original from Xiaomi with Quick Charge support) 3.0/4.0 or PD). If the speed has increased - the problem in the power supply.
• 📱 Try another cable. Cheap cables often have thin veins that can't withstand high currents. Xiaomi's original cables are labeled with the inscription. 5A.
• 🔍 Check the connector. USB-C It's on your phone and charger, and oxidation (green coating), contamination, or strain of your contacts, reduces your charging speed.

For modern Xiaomi smartphones (for example, Xiaomi 13 Pro or Redmi Note 12 Pro+), the minimum recommended power is 33W. If you use a 10W or 18W unit, the phone will charge 2-3 times slower, even if you previously “suffered” such a memory.

⚠️ Warning: Some smart sockets and extensions limit the power of the connected devices. Try connecting the charging directly to the network outlet.

2.Diagnostics of USB-C connector on the phone

The USB-C connector is the most vulnerable part of the charging chain, and the dust, moisture, and frequent connections/disconnections of the cable cause the contacts to oxidize or damage mechanically.

Light the connector with a flashlight and check for debris.

Carefully remove dust with a toothpick (not a metal object!)

Wipe the contacts with an alcohol napkin (without pressing)

Blow the connector with compressed air (cylinder for technology)-->

If the speed has not increased after cleaning, the problem may be deeper:

• 🔧 Bending contacts -- common after a phone crash. Solution: only replacing the service connector.
• 💧 Corrosion from moisture - if the phone was in contact with water, oxidation could spread to the board, in which case only professional ultrasound cleaning will help.
• 🔌 Untwisted connector -- soldered contacts move away from the board over time, sign that the cable is not tight, charging is interrupted with light movement.

Critical: if the phone only charges in a certain position of the cable, it is a sure sign of mechanical damage to the connector.

Checking the status of the battery

The battery is the second most popular culprit for slow charging, and over time, its capacity decreases and internal resistance increases, causing the power controller to limit current.

1. Go to Settings → Battery Status (on MIUI 14, the path may differ: Settings → Battery → Battery Status).
2. Note the "Degree of Wear" option, which is more than 20%, and the battery needs to be replaced.
3. Use the AccuBattery app (available on Google Play) for a detailed diagnosis, which will show real capacity, charging current and temperature.

If the degree of wear is high, but you can’t replace the battery right now, try calibrating the battery:

1. Discharge the phone before automatically shutting down.
2. Connect to the original RAM and charge for at least 8 hours (even if the indicator shows 100%).
3. Turn off the network, turn off the phone for 5 minutes, then turn it on.

4. Software failures and MIUI settings

MIUI is known for its “optimizations” that sometimes work against the user, and if the phone has started to charge slowly after an update or reset, it may be:

• 📱 Background restriction: MIUI By default, it blocks application background activity, which can affect charging processes. → Battery → Background restriction.
• ⚡ Power saving mode: even if it's off, some settings may have been saved. → Battery → Energy saving regime → Settings and disable “Optimizing charging».
• 🔄 Power controller failure: sometimes resetting the battery settings helps. → System system → Resetting settings → Resetting battery settings.

If the problem has occurred after the MIUI update, try rolling back to the previous version (if available) or reset to factory settings.

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After resetting the battery, the phone can charge more slowly in the first 2-3 cycles. This is normal: the system calibrates new parameters.

5. overheating of the phone while charging

Xiaomi’s power controller automatically reduces the charging current if the battery temperature exceeds 40–45°C.

• 🌡️ Using your phone while charging (games, videos, navigation).
• ☀️ Direct sunlight or charging in a hot room.
• 🔥 Faulty battery (swelling, short circuit).
• 📦 Heat-locking case.

How to check the temperature:

1. Install the AIDA64 app (available on Google Play).
2. Go to the Sensors section and look at the battery temperature.
3. If it is above 45°C, disconnect the phone from charging and let it cool.

⚠️ Warning: If the phone is heated to 50°C+ Standby, stop using immediately! This is a sign of battery short circuit - risk of fire!

6. Problems with firmware and power controller

In rare cases, slow charging is associated with a power controller firmware failure (for example, after a failed update or "firmware" via Fastboot).

• The phone is charged only when it is off.
• The charging speed “jumps” (it is 10W, then 30W for no reason).
• Charging stops by 80-90%.

Decisions:

1. Reset to factory settings (via Settings → System → Resetting).
2. Flashing through the Mi Flash Tool (only for power users!).
3. Update via Recovery: 1. Turn off the phone. 2. Press <power button> + <volume button> until the Mi Recovery logo appears. 3. Select "Update via ADB" and connect the phone to the PC. 4. In the command line, type: adb sideload [name file firmware.zip]

External factors: from the network to the weather

Sometimes the problem isn't with the phone, it's with the environment, and here's what can affect the charging speed:

• ⚡ Unstable voltage on the network: if you often flash lights, the charger may not give out full power. UPS.
• 🌧️ Humidity or cold: at temperatures below 0°Lithium-ion batteries charge 2-3 times slower. The same applies to humidity above 80%.
• 📶 Weak network signal: In poor coverage (such as in the subway), the phone spends a lot of energy searching for the network, which slows down charging.
• 🔋 Power Bank poor quality: many external batteries do not give out the declared power.

If you charge a phone from Power Bank, pay attention to its power output. for example, for Xiaomi 12T Pro (support) 120W) Even Power Bank. 30W will not be sufficient.

8. When is the time to contact the service?

If you’ve tried all the methods but your phone still charges slowly, the problem may be:

• 🔧 Faulty power controller (requires chip replacement).
• 🔋 Bloated battery (visually visible on the "bloated" body).
• 🔌 Damaged motherboard (for example, after falling or getting moisture).

Signs that you need professional help:

• The phone does not charge at all or only charges when it is off.
• There is a smell of burning or smoke when connecting the charging.
• The battery is swelling (the phone body is "unplugged").
• The charging speed dropped after falling, hitting or contacting water.

⚠️ Warning: Don't try to disassemble your phone yourself unless you have experience! Mishandling lithium-ion batteries can lead to a fire or explosion.

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If the phone is warranty, do not open it yourself! Contact the authorized service center Xiaomi - repair warranty free.

FAQ: Frequent questions about Xiaomi's slow charging