Xiaomi Redmi 8 Pro is a popular smartphone with a capacious battery of 4500 mAh, but sometimes users face the problem: the device charges obscenely long. Instead of the promised 2-3 hours to 100%, the process stretches for 5-6 hours or more. What is the reason and how to return fast charging?
In this article, we will examine all possible causes, from the banal (damaged cable) to the hidden (power controller malfunction), you will learn how to diagnose a problem, what settings to check in MIUI, and when to carry the phone to the service. And also - unique nuances for the Redmi 8 Pro, which are not found in other Xiaomi models.
1. Checking of charger and cable
Start with the simplest: 90% of slow charging problems are related to poor-quality accessories. Redmi 8 Pro supports fast 18W charging, but only when using original or certified RAM. If you connect your phone to a laptop, power bank or cheap adapter, the speed will drop to 5W-10W.
How to check:
- 🔌 Try another cable and power supply (preferably original from Xiaomi or proven brands: Anker, Baseus, UGreen).
- 🔍 Examine the cable for insulation damage or bending - they disrupt current transmission.
- 📱 Connect the Redmi 8 Pro to another device (for example, a tablet) – if charging is fast, the problem is the original RAM.
- 🔋 Check the power supply: it should be indicated 5V/3A, 9V/2A or 18W.
⚠️ Attention: Cheap cables with AliExpress often have thin veins that can not withstand current 2A–3A. Not only does this slow down charging, it can also damage the port. USB smartphone.
2. Clean USB port and contacts
Dust, pile or contact oxidation in a USB Type-C connector is a common cause of poor contact. The Redmi 8 Pro is particularly sensitive to this because of the port's design: it's slightly recessed into the case, which contributes to the accumulation of debris.
How to clean the port:
- Turn off the phone and get it out. SIM-card (just in case).
- Light a flashlight into the connector – if debris is visible, carefully remove it with a plastic or wooden toothpick (NOT metal!).
- To remove oxidation, wipe the contacts with a cotton swab dipped in isopropyl alcohol (90%+).
- Allow the port to dry for 10-15 minutes before connecting the cable.
⚠️ Warning: Do not use compressed air (canisters) - it can drive dust deeper into the port. Also avoid liquids based on acetone - they corrode plastic.
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If the charging is still slow after cleaning, try wiggling the cable slightly in the connector during the connection, and if the speed changes, the problem is mechanical wear on the port.
3. Battery settings and energy saving modes
MIUI has aggressive power optimization algorithms that can artificially limit charging current. The Redmi 8 Pro has two key parameters:
- Smart Charging Mode (Settings → Battery → Battery Settings): If turned on, the phone slows down charging after 80% to keep the battery healthy.
- Charging optimization (Settings → Battery → Charging optimization): can limit current at high temperature or long connection.
How to disable restrictions:
Turn off "Smart Charging" in the battery settings |
Turn off "Optimizing charging" |
Make sure that the Performance mode is on (Settings → Special Opportunities → Performance)|
Reboot your phone after the changes-->
Also check if the power saving mode is on (Settings → Battery → Power saving mode) and it automatically limits the charging current to 1A-1.5A.
Checking the status of the battery
If the Redmi 8 Pro has been in use for more than 2-3 years, the problem may be a degraded battery, which over time, the battery capacity drops, and internal resistance increases, which leads to:
- 🔋 Slow charging (especially in the last 20 years%).
- 🔥 Overheating during charging.
- ⚡ A sharp drop in percentage of charge after disconnection from the network.
How to check the health of the battery:
- Enter the code in your phone number: ##4636## → Select Battery Information.
- Look at charge level, condition and temperature. The normal temperature for charging is 30-40°C.
- Use the AccuBattery app (available on Google Play) for detailed diagnosis.
| Parameter | Norma. | Critical significance |
|---|---|---|
| Battery capacity | ≥ 4000 mAh | < 3000 mAh (75% of the original) |
| Temperature during charging | 30–40°C | > 45°C |
| Charging time 0-100% | 2.5 hours | > 4 hours |
| Charging speed (current) | 1.5A–3A | < 0.5A |
⚠️ Note: If the battery capacity has fallen below 70% of the original (i.e. less) ~3150 mAh), it needs to be replaced, and further use can cause the phone to suddenly shut down or the battery to bloat.
5. Software failures and resetting of settings
Sometimes slow charging is caused by firmware failures or application conflicts, especially after MIUI updates. Redmi 8 Pro is known for bugs with:
- 🤖 Background optimization (apps like Facebook or Telegram can block normal charging).
- 🔄 Cache system (clogged cache leads to lags and improper operation of the power controller).
- 📱 Developer settings (for example, the screen turned on may interfere with charging optimization).
What to do:
- Clear the system cache: Settings → Memory → Clear the cache
- Reset battery settings: Settings → Applications → Application management → Three dots (menu) → Reset battery settings
- Perform a reset to factory settings (if nothing helped): Settings → The phone. → Resetting settings → Erase all data ⚠️ Pre-return the backup copy!
How to check if a specific application interferes with charging?
Hardware malfunctions
If all software methods have been tried and the Redmi 8 Pro is still charging slowly, it is likely a hardware problem.
| Malfunction | Signs. | Decision |
|---|---|---|
| Charging controller damaged | The phone does not recognize the original RAM, charges only from USB 2.0 | Replacement of the controller (solding required) |
| Oxidation/breaking of tracks on board | Charging is jerky, the phone periodically disconnects from the network | Diagnostics in the service, repair of fees |
| Faulty. USB-port | The cable is not tight, charging is interrupted at the slightest movement. | Replacement of Type-C connector |
| Bloated battery | The phone body is deformed, the screen “steps away” from the frame | Replace the battery immediately! |
⚠️ If you notice that your phone is heating up to 50.°C when charging or battery swells - immediately disconnect it from the network and do not use until repair!
For hardware problems, you should contact the service center.Average repair cost for the Redmi 8 Pro:
- 🔧 Replacement USB-port: 1,500–2,500 ₽.
- 🔋 Battery replacement: 2,000–3,000 ₽ (battery-powered).
- 📱 Board repair (charge controller): 3000–5,000 ₽.
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If the phone stopped charging quickly after falling, getting moisture or disassembling itself, 99% of the blame lies with a hardware malfunction.
7. Alternative methods of accelerating charging
If you are temporarily unable to eliminate the cause of slow charging, use these tips to speed up the process a little:
- ❄️ Charge your phone in a cool place (such as near the air conditioner) at temperatures below 25.°C charging is more efficient.
- 📵 Turn on the plane mode - this will turn off background processes that consume energy.
- 🔕 Turn off your phone while you charge (slows it down by 15-20%).
- 🔋 Use the "Fast Charging" function in MIUI: Settings → Battery → Fast charging (should be enabled by default, but sometimes resets after updates).
⚠️ Note: Do not use wireless charging for the Redmi 8 Pro – this model does not support it, and adapters with a Qi receiver give current no more 5W (slowly!).