Why fast charging doesn’t work on Xiaomi Redmi 8 Pro: 7 reasons and how to fix it

Xiaomi Redmi 8 Pro proudly positioned as a budget smartphone with support for fast charging 18W — a rarity in its segment in 2019. But over time, many users are faced with the fact that the device stops charging in accelerated mode: instead of the promised 1-2 hours to 100%, the process is stretched for 3-4 hours, and in the status bar shows the inscription “Charging (normal)”.

The problem is not only battery wear — MIUI software failures, unoriginal accessories, and even mechanical damage to the USB-C port can be to blame. In this article, we will analyze all possible scenarios, from banal (contaminated connector) to critical (power controller failure), and also give unique diagnostic recommendations that you will not find in Xiaomi standard instructions, for example, how to check the real charging power without special devices or why resetting the settings to the factory can aggravate the problem.

1. Power supply and cable check: why 18W turns into 5W

The first thing to rule out is the charging accessories mismatch. Redmi 8 Pro supports Quick Charge 3.0, but only if three conditions are met:

• 🔌 The power supply must produce a minimum of 18W (9V/2A or 12V/1.5A). The standard "brick" of the kit just matches these parameters.
• ⚡ The cable must support data transmission and high current. Cheap cables are often limited 1-1.5A, which automatically puts charging into slow mode.
• 🔄 The port USB-C on the smartphone and the power supply must be clean and intact, and oxidation or contamination of the contacts violates the power agreement between the devices.

How do you check? Connect your smartphone to charge and go straight to Settings → Battery. If the power chart shows below 10W, the problem is precisely in the accessories.

⚠️ Warning: Never use power supplies from other devices with power above 18W (e.g., laptops) that could cause the Redmi 8 Pro power controller to overheat and fail.

2 Software Failures MIUI: Why the System “Strikes” Charging

The MIUI operating system sometimes artificially limits the charging power due to:

• 🔄 Battery settings are wrong, for example, if you turn on Charge Saving or Ultra-Economic Mode, you automatically reduce the charging speed.
• 📱 Firmware bugs, especially since the MIUI 12.5+ update, where Xiaomi tightened power controls.
• 🚫 Prohibits fast charging in developer settings (yes, it happens!).

To exclude the programmatic reason:

1. Go to Settings → Battery → Battery Modes and turn off all saving modes.
2. Open Settings → About the phone, tap 7 times on the MIUI version to activate the developer mode.
3. Return to Settings → Additional → For developers and find the item “Unplug the charging restriction” (if any).
4. Reset settings → System → Reset settings → Reset battery settings.

Turn off battery saving modes |

Check the developer's settings |

Reset battery statistics |

Update MIUI last-minute-->

If the charging didn’t accelerate after these manipulations, try rolling back the firmware to an older version (for example, from MIUI 13 to MIUI 12.5).

Battery wear: when 4,000 mAh is no longer the 4,000 mAh

The Redmi 8 Pro lithium polymer batteries (BM47) have 500 full charge cycles, and then the capacity drops by 20 to 30 percent, and the power controller starts to limit the current to extend the battery life. How do you check the wear?

Go to Settings → Battery → Battery status. If it says "Good" or "Normal", the battery is fine. If "Replace the battery" - it's time to think about replacing.

• ⚡ Battery life (if the smartphone is discharged in 4-5 hours with moderate use – the capacity is critically low).
• 🔥 Overheating during charging (over 40°C is a sign of degradation of elements).
• 📉 Sharp jumps in charge level (for example, from 50% to 20% per minute).

⚠️ Warning: If you choose to replace the battery yourself, use only the original battery BM47 or certified analogues (e.g., from ZMI). Cheap fakes may not support Quick Charge 3.0 and may even cause a fire.

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Before replacing the battery, check it for authenticity: the original Xiaomi battery has a hologram with the brand logo and QR- code, which can be scanned through the Mi Verify app.

4 Mechanical damage: USB-C port and power controller

The Redmi 8 Pro is not well protected from moisture (no IP certification), so liquid or dust entering the USB-C port is a common cause of charging problems.

• 🔍 Visual inspection: illuminate the port with a flashlight – if oxidation (green plaque) or contamination is visible, cleaning is required.
• 🔌 Test with another cable: If charging is only at a certain angle, the contacts inside the port are likely to be bent.
• 💧 Corrosion check: If the smartphone fell into water or was in a wet environment, the power controller could fail.

To clean the port, use a wooden toothpick (not metal!) and isopropyl alcohol (90%+). If the problem is bent contacts, they can be bent neatly with a needle, but it is better to contact the service. The damaged power controller (located on the motherboard next to the USB-C port) cannot be replaced by yourself - soldering is required.

5. Application conflict: Who is "stealing" power?

Some applications in the background consume so much power that the MIUI system forcibly reduces the charging power to avoid overheating.

• 🎮 Games (PUBG Mobile, Genshin Impact) if they are running while charging.
• 📷 Applications for shooting video in 4K or streaming (TikTok, Twitch).
• 🔄 Optimizers and cleaners (Clean Master, DU Speed Booster) that aggressively shut down processes.

How to check:

1. Connect charging and open Settings → Battery → Battery use.
2. See which apps consume >5% charge in the background.
3. Close them through recent apps and check if the charging speed has changed.

If a particular application is to blame, add it to the optimization exceptions:

1. Go to Settings → Applications → Application Management.
2. Select the problem app → Battery Savings → No restrictions.

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Even if the app is not active, its background processes (such as syncing Google Photos or WhatsApp) can reduce charging speeds by 30-40%.

6. Factory reset: panacea or risk?

Sometimes users are advised to do a full reset as a universal solution, but for the Redmi 8 Pro, it can be dangerous.

• 🔄 After resetting, MIUI may “forget” the battery calibration, causing charging to stop by 80-90%.
• 📱 If the problem is in the firmware, reset will not help - you need to reflash the device through Fastboot.
• 🔌 In rare cases, a reset resets the power controller settings and the fast charging disappears forever.

If you're still going to reset:

1. Make a backup through Settings → System → Backup.
2. Go to Settings → About Phone → Reset settings and select Delete all data.
3. After a reboot, don’t restore data from the cloud right away – check charging first.

⚠️ Warning: If the fast charge didn’t return after the reset and the battery says “Charge suspended” in Settings → Battery, immediately disconnect the smartphone from the network. This is a sign of a power controller failure – further charging could damage the battery.

7. Alternative methods: if nothing has worked

If all of the above methods do not work, radical measures remain:

For firmware via Fastboot:

1. Download the latest version of MIUI for Redmi 8 Pro (codenamed Olivelite) from xiaomifirmwareupdater.com.
2. Unpack the archive and connect the smartphone to the PC in Fastboot mode (clip Volume down + Power).
3. Run the script. flash_all.bat (Windows or use the command: fastboot flash all

If you are not sure about your skills, it is better to contact the service center. The average cost of diagnosing Redmi 8 Pro is 500-1000 rubles, replacing the USB-C port is 1500-2500 rubles.

FAQ: Frequent questions about Redmi fast charging 8 Pro