How to turn on fast charging on Xiaomi Redmi 8: all the ways and nuances

Xiaomi Redmi 8

fast-charging

MIUI

Quick Charge

It’s important to understand that the Redmi 8 is equipped with a 5,000 mAh battery, and its charging from a standard 5-watt power supply can stretch for 4-5 hours. 18W, But it requires not only the right adapter, but also the right software settings, and if you've tried charging your phone with the original charger, but the result didn't live up to expectations, don't be quick to blame the hardware, because 80 percent of the time, the problem is solved at the software level.

We'll go into detail next:

🔌 How to check the compatibility of the charger and cable
⚙️ What settings? MIUI affect the charging speed
🔋 Why Smartphones Can Limit Current Even With Original Adapter
🛠️ Methods of eliminating software failures that interfere with fast charging

📊 You are using the original charger from Xiaomi?

Yeah, just the original.

No, third-party adapter.

I don't know what my Zoo is.

I use the power bank.

1. Checking the compatibility of the charger and cable

The first thing to do is make sure your charger and cable support fast charging technology. Xiaomi Redmi 8 is compatible with Quick Charge 3.0 standards and USB Power Delivery (up to) 18W), but only if two conditions are met:

The power adapter must be given out 9V/2A or 12V/1.5A (minimum requirements for QC 3.0).
The cable must support data transmission and current up to 3A (This is usually a USB Type C or a high-end Micro USB labeled 3A).

Original Redmi kit 8 plug-in 10W (5V/2A), It doesn't provide the maximum charging speed. It's going to require you to buy a separate Quick Charge to activate it:

🔌 Xiaomi Charger 18W Quick Charge 3.0 (article) MDY-08-EM)
🔗 Cable USB Type-C → USB Type-A with support 3A (For example, the original from the Redmi Note 8 Pro)

How to check the current charger?

Check the label on the adapter: the values should be indicated 9V/2A or 12V/1.5A.
Use the Ampere app (available on Google Play) to measure the actual charging current. For fast charging, the value should exceed 1500 mA.
Note the connector: Redmi 8 uses Micro-USB, but for maximum speed it is better to upgrade to Type-C via an adapter (although this is an unofficial solution).

⚠️ Caution: Cheap cables without high-current support can overheat and automatically limit charging power to 5W. If your smartphone heats up in the area of the connector – urgently replace the cable!

2. MIUI settings affecting charging speed

MIUI It has a few hidden and explicit parameters that can block fast charging. Even if you use a compatible adapter, the system can artificially limit current due to power saving or battery protection settings.

The first thing to do is to turn off charging optimization:

Go to Settings → Battery and Performance → Battery Settings
Find the charge optimization item and turn it off.
Also deactivate Adaptive Charging (if any).

Second, check the performance mode:

🔧 Go to Settings. → The phone. → Version. MIUI (Tap 7 times to activate Developer Mode).
Back to Settings → Additionally. → For developers.
Find the Background Limitation and select No Limits.
Activate Debugging on USB (Sometimes it removes software charging locks).

Third, reset Battery Stats settings (if the smartphone has previously worked with slow charging):

1. Connect the phone to the charger.


2. Launch Engineer Mode (code ##4636##).)




3. Go to Battery Information → Battery Usage.




4. Press Reset Stats and restart the device.

The optimization of charging in MIUI

Supported cable is used 3A

Adapter gives out 9V/2A or 12V/1.5A

Reset battery statistics (via Engineer Mode)

Developer mode activated (without background restrictions)-->

3.Why can Redmi 8 ignore fast charging?

Even with the right setup and compatible hardware, the Redmi 8 sometimes refuses to charge at full power.

Problem.	Reason.	Decision
Charging is on. 5W though QC-adapter	Overheating protection worked.	Cool your phone (reduce brightness, close apps) and reconnect
The charging current jumps (500 mA, then 1500 mA)	Faulty cable or oxidation of the connector	Clean the port with alcohol, replace the cable
Fast charging only works up to 80%	The function "Charge up to 80%" is activated MIUI	Turn off the Settings. → Battery → Battery health
Adapter warms up, but phone charges slowly	Unoriginal adapter with poor voltage stabilization	Use only certified RAM (e.g. Xiaomi) 18W QC 3.0)

The Redmi 8 automatically reduces the charging current if:

🌡️ Battery temperature exceeds 40°C (checked through AIDA64).
🔥 Processor loaded (games, video rendering).
☀️ The phone is under direct sunlight.

If the smartphone is heated, fast charging is activated only after cooling to 30-35°C. To speed up the process:

Take off the case.
Put your phone in Airplane Mode.
Use a cooling stand (if available).

What if the fast charging suddenly stopped working?

Suddenly fast charging stopped working, try these steps: 1. + Volume up for 10 seconds. 2. Update MIUI: Install the latest firmware version through Settings → System Update. 3. Port Check: Check the connector for damage (curved contacts, debris). 4. Factory reset: If nothing helps, reset to Settings → Recovery and reset (pre-save data!).

4. Programmatic failures and their elimination

Sometimes fast charging is blocked due to errors in work. MIUI Or conflicts with installed applications. Let's look at typical scenarios:

Resetting the battery cache (works in 60% of cases):

1. Turn off the phone.


2.Put Power + Volume up until the Mi logo appears.




3. From the Recovery menu, select Wipe & Reset → Wipe Cache.




4. Reset the device.

Conflict with annexes:

📱 Some programs (e.g. Greenify, AccuBattery) can block fast charging.
🔍 Check the permissions of applications in Settings → Annexes → Permits → Special access.
🚫 Temporarily remove applications to optimize the battery.

Firmware update:

Old versions. MIUI (There were bugs below 12.0.3) with Quick Charge recognition:

Go to Settings. → Updating the system.
Click Check for updates.
If you have a new version, install it (preferably via Wi-Fi).

⚠️ Attention: After update MIUI Sometimes you reset your battery settings. Re-activate Charging Optimization and check the current through Ampere!

5. Alternative methods of accelerating charging

If standard methods don't work, you can try workarounds, which don't always give you a full-fledged fast charge, but they speed things up by 20 to 30 percent.

Using Power Bank with the QC 3.0:

🔋 Some external batteries (e.g. Xiaomi Mi Power Bank 3 Pro) support 18W.
📱 Connect Redmi 8 to such a power bank - it can be recognized as a power bank. QC-charger.

No restrictions mode (only for experienced users):

Through ADB You can disable all software charging restrictions:

adb shell


su




settings put global fast_charge_forced_enable 1

⚠️ This method requires root rights and can shorten battery life!

Replacement of firmware with custom:

Firmware like Pixel Experience or LineageOS are often better optimized for charging, but it’s a risky move:

✅ Pros: stable fast charging, no background restrictions.
❌ Cons: loss of warranty, possible bugs with iron.

💡

If you frequently charge your phone at work or in the car, buy a magnetic cable with support. QC 3.0. It prevents damage to the connector during sudden movements and maintains the charging speed.

6.How do you check that fast charging is actually working?

Many users think their Redmi 8 charges fast, but the current is actually limited. 10W. To make sure that Quick Charge works, follow the following steps:

Method 1: Appendix Ampere

Install Ampere from Google Play.
Connect the phone to the charger.
Start the application: if the current value exceeds 1500 mA, fast charging is active.

Method 2: Charging time

The full charging cycle of Redmi 8 (0–100%) should take:

🔌 10W (Standard adapter: 4-5 hours.
⚡ 18W (Quick Charge: 2–2.5 hours.

If your phone charges for more than 3 hours, fast charging doesn’t work.

Method 3: Notification in the status line

When Quick Charge is activated, a notification should appear in the status bar:

📱 Fast charging (in English firmware - Fast charging).
🔋 Battery icon can flash or display lightning.

💡

If the Ampere app shows current below 1000mA when used QC-Adapter, so fast charging is not activated. MIUI.

7. Frequent errors and myths about fast charging

There's a lot of rumors going around about Quick Charge, and we're going to take a look at some of the most common misconceptions.

Myth 1: “Fast charging ruins the battery”

❌ Partly true, but not critical: Modern lithium-polymer batteries are designed to last 500 to 800 cycles, regardless of charging speed.°C) really shortens the lifespan. Solution: don't charge your phone in the sun and don't play heavy games while charging.

Myth 2: “Any adapter on the 18W will work"

❌ Not all adapters are labeled 18W Quick Charge 3.0 is supported, for example, cheap Chinese RAMs can be issued 18W standard-only USB Power Delivery, which isn't always compatible with Redmi 8. QC 3.0 on package.

Myth 3: “You need to discharge your phone to 0% to calibrate.”

❌ This is an outdated recommendation for nickel batteries. Lithium polymer batteries in Redmi 8 do not require full discharge. Optimal charging range: 20-80% (this extends the life of 30 years%).

Myth 4: “Wireless charging is faster than wired charging”

❌ Maximum wireless charging power for Redmi 8 — 10W (against 18W In addition, induction charging heats the phone more, which leads to a restriction of current.

Can I use a charger from the Redmi Note 8 Pro for the Redmi 8?

Yes, adapter from Redmi Note 8 Pro (18W QC 4+) Fully compatible with the Redmi 8 and providing maximum charging speeds, but the original cable is better used, as the Note 8 Pro comes with Type-C, and the Redmi 8 requires a Micro-USB (or adapter).

FAQ: Answers to Frequent Questions

Can I turn on fast charging on the Redmi 8 without the original adapter?

Yes, but only if the third-party charger supports Quick Charge. 3.0 or USB Power Delivery with parameters 9V/2A. Cheap adapters on the 18W Check the certification on the packaging.

Why does fast charging only work up to 80% and then slow down?

It's normal behavior. MIUI. After 80 percent, the system automatically reduces the current to reduce heat and extend battery life, and you can only turn it off via Engineer Mode or ADB (see section 4).

Should I use fast charging constantly?

For everyday use, yes, but avoid charging in extreme temperatures (below 0)°C or higher than 40°It is also not recommended to keep the phone on charge all night: after 100% MIUI goes into recharging mode, which creates microcycles and over time reduces the capacity of the battery.

Can you speed up the charging through USB-port?

No. USB-Computer ports give the maximum 2.5W (5V/0.5A), what 7 Quick Charge is slower than Quick Charge. USB 3.0 (blue connector -- it gives you up. 4.5W, But it's still not enough to charge fast.

What if the MIUI update stopped working fast charging?

This is a well-known problem with some versions. MIUI Solutions: Reset the battery settings via Engineer Mode (code ##4636##.) Reverse to the previous firmware version (if available). Install a custom core (e.g. FrancoKernel) if there is root.