How to improve the Xiaomi Redmi 9: from optimization to upgrade

Xiaomi Redmi 9, released in 2020, is still a popular budget smartphone due to its balanced characteristics: the MediaTek Helio processor. G80, 4 GB of RAM and a capacious battery for 5020 mAh. However, over time, even this reliable device begins to “brake”, quickly discharge or overheat, the reasons are not in the “weak iron”, but in the accumulated digital debris, outdated settings and suboptimal use of resources.

In this article, 10 practical ways to bring the Redmi 9 back to (or even surpass) factory speed, extend battery life, and fix typical problems. MIUI 12-14 and they don't require root rights, and if you're ready for radical measures, we'll end up with a look at whether to change firmware to custom and how to do it without the risk of "bricking" the phone.

1.Diagnosis: Why did Redmi 9 get slower?

Before optimizing, you need to understand the root of the problem. Redmi 9 has three bottlenecks that are most often to blame for lags:

• 📱 Overloaded memory: MIUI It actively caches applications, and over time, temporary files occupy up to 30% of internal storage.
• 🔋 Degraded battery: After 300-500 charging cycles, the capacity drops by 15-20%, which causes the processor to artificially limit performance.
• 🤖 Outdated software: firmware older MIUI 13 contain errors in memory management, which is why background processes “eat” up to 1 GB of RAM.

To determine the culprit, perform a quick check:

1. Open Settings → About Phone → MIUI version and check the relevance of the firmware.
2. Run Settings. → Battery. → Battery status (if no item – use the AccuBattery app).
3. Install. CPU Monitor from Google Play and see if the processor loads more than 70% in idle.

⚠️ Warning: If the phone reboots when charging below 20%, it is a sign of critical battery wear. Software optimization will not help here: battery replacement is required.

2. Cleaning the system: remove garbage and cache

Redmi 9 on the MIUI It has a nasty feature: even after deleting applications, their cache and residual files can take up to 5-7 GB of memory:

Step 1 System cleaning

• 🧹 Go to Settings. → Warehouse → Clean up and click on “Clean up garbage».
• 🗑️ In the same menu, select “Free space” and remove unnecessary ones. APK-files, downloads and duplicate photos.
• 🔍 Open the Settings. → Annexes → Manage applications, sort by size and remove unused programs.

Step 2. Deep cleaning of the cache (requires) ADB):

adb shell pm trim-caches 1000000000

This command compulsorily clears the cache of all applications. Connect the phone to the PC, turn on Debugging. USB (Settings → The phone. → Version. MIUI → 7 times press the version and execute the command in the terminal.

Step 3. Shutdown MIUI-bloke

MIUI The default installs a lot of unnecessary services (for example, Mi Video, Mi Music, GetApps) They can not be removed without root, but you can turn off:

1. Go to Settings → Applications → Application Management.
2. Find an unnecessary app (e.g. Mi Browser) → «Shut down».
3. Confirm the action – the application will “freeze” and stop working.

⚠️ Note: Do not disable system services called com.android. or com.xiaomi. MIUI (For example, Bluetooth or the camera will stop working).

3. Performance optimization: Overclocking without root

MediaTek Helio G80 Redmi 9 is a good processor, but MIUI It's the default limiting its potential. Here's how to unlock hidden possibilities:

Method 1. Installing the performance mode

• 🚀 Go to Settings. → Battery → Performance mode.
• 🔧 Select “High Performance” (in some firmwares, this item is hidden – use Developer Options).

Method 2: Set up animation (requires the developer mode to be enabled):

1. Activate Developer Mode (7 times click on the MIUI version in Settings → About Phone).
2. Go to Settings → Additional → For developers.
3. Find the items: The scale of window animation → Off. Scale of transition animation → Duration of animation → 0.5x

Method 3: Limitation of background processes

MIUI By default, it allows applications to run in the background without restrictions:

1. In For Developers, find Process Limitation.
2. Select “Maximum 2 Processes in the Background” (this won’t kill messengers, but will reduce the load on RAM).

How to regain autonomy:

Step 1: Calibration of the battery

1. Discharge your phone to 0% (until it turns off on its own).
2. Connect the original charger and charge up to 100% without interruptions.
3. After full charging, keep the phone charging for another 2 hours.
4. Perform a reset of battery statistics: Settings → Battery. → ⋮ → Resetting statistics.

Step 2: Optimizing charging

• ⚡ Use only the original adapter 18W (Quick Charge 3.0 certified).
• 🔋 Do not allow a discharge below 20% and a charge above 80% in everyday use.
• 🛌 Charge your phone at night in the plane mode – this reduces heating.

Step 3: Configuring energy saving

B Settings → Battery:

• Turn on the “Adaptive Battery” (artificial intelligence) MIUI cost-optimizing).
• Add frequently used apps (messengers, maps) to the “Energy Saving Exclusions” section.
• Turn off Auto Brightness and set a fixed value of 50-60% (adaptive brightness often works incorrectly).

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If your phone is running out of more than 10% overnight, check the app activity in Settings. → Battery. → Battery use: Google Play Services or MiuiDaemon are the ones most often to blame, and they can be manually restricted.

5. Firmware update: MIUI vs custom assemblies

Official updates to Redmi 9 (codenamed lancelot) are rare, but they are critical to stability. On the other hand, custom firmware like LineageOS or Pixel Experience promises “pure Android” and better performance.

How to update the official firmware:

1. Go to Settings → About the phone → System update.
2. If the update is available, download it over Wi-Fi (file weighs) ~2 GB).
3. Before installing, make sure that the battery is >50%.

How to install custom firmware (briefly):

The process requires unlocking the bootloader and installing TWRP. Main steps:

1. Unlock the bootloader through Mi Unlock Tool (you need a Xiaomi account and wait 7 days).
2. Install. TWRP For lancelot via fastboot:
3. V TWRP Make a backup. → System + Data).
4. Sweep through custom firmware and GApps (if you need Google services).

⚠️ Attention: Installing custom firmware voids warranty and can lead to data loss.On Redmi 9 with custom firmware often VoLTE does not work (calls on the phone). 4G).

Iron Upgrade: What Can Be Improved Physically?

If the software methods don't work, you can upgrade the components. Redmi 9 can replace:

• 🔋 Battery: Original Battery BY41 worth ~1500–2000 ₽. After replacement, autonomy is restored to 90% of the new.
• 💾 Memory: The model supports microSD up to 512 GB (class) A2 speed up applications).
• 📶 Antenna module: if the network catches poorly, you can replace the antenna cable (~500 ₽).

How to choose a battery:

Buy only batteries with labels. BY41 and capacity of 5020 mAh. counterfeits often have a real capacity of 3000-4000 mAh:

• AliExpress (Xiaomi Original Store or Mi Global Store)
• Beru/Ozon (higher-rated sellers 4.8).

Self-replacement of the battery:

1. Turn off the phone and remove it. SIM-map.
2. Heat the back cover with a hair dryer (temperature 60-70 ° C) and put it under a plastic spatula.
3. Unscrew 10 Phillips screws #00 and disconnect the battery plume.
4. Carefully tuck the battery and replace it with a new one (use glue). B-7000 fixative).

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If the phone doesn’t turn on after replacing the battery, check the connection of the display plume – it could have left during assembly.

7.Alternative launchers and optimized applications

MIUI It's known for its heavy launcher, which consumes up to 300MB of RAM. Replace it with lightweight alternatives:

How to install the launcher:

1. Download APK from APKMirror (like Nova Launcher).
2. Install the file and allow access to the storage.
3. Click "Home" and select the new launcher as the main one.

Optimized replacements for standard applications:

• 📷 Camera: Google Camera (GCam) for lancelot (best photo processing at night).
• 🎵 Music: VLC Musicolet (does not consume background resources).
• 📱 Browser: Bromite (blocking ads) + speed).

8. Radical methods: resetting and flashing

If nothing has worked, radical measures remain:

Method 1: Hard Reset (Hard Reset)

Restores the phone to factory settings, deletes all data.

1. Turn off the phone.
2. Press Volume Up + Power before the Mi logo appears.
3. Select Wipe Data → Wipe All Data (Change Volume Buttons).
4. Confirm the action and wait for the reboot.

Method 2. Fastboot flashing

If the phone doesn’t turn on or is “hinged” on the logo, flash the official firmware manually:

1. Download Mi Flash Tool and firmware for lancelot from the official website.
2. Start the phone in Fastboot mode (Loudness down). + Nutrition).
3. Connect to your PC and in Mi Flash, select Clean All.
4. Press Flash and wait until it is finished (10-15 minutes).

⚠️ Warning: Fastboot flashing erases all data, including photos on internal memory. If the phone is recognized by a PC, first make a backup through the computer. ADB: adb pull /sdcard/ ~/redmi9_backup/

Method 3: Unlocking the bootloader and the custom core

For advanced users, cores like Perseus or FrancoKernel can improve performance by 20 to 25 percent, but require:

• Unlocked bootloader.
• Installed TWRP.
• Backup copy boot.img.

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Hard reset solves 80% of software problems, but does not help with the physical wear and tear of components (for example, batteries or flash memory).

FAQ: Frequent questions about Redmi 9