Why the memory card is not defined in Xiaomi 9A and how to fix it
Owners of Xiaomi Redmi 9A There's a problem that we're often faced with, you put in a microSD and your phone doesn't see it, and there's a lot of reasons, from the wrong formatting to the hardware limitations of the model. In this article, we'll look at all the ways you can connect a memory card, including the hidden settings. MIUI, I would like to explain why the system sometimes uses SD-The card is only a portable storage, not an extension of internal memory.
The Redmi 9A (codename dandelion) features a budget MediaTek Helio G25 processor and Android 10/11 firmware with MIUI 12/13 shell. These factors affect the work with external drives. For example, the phone supports cards up to 512 GB, but only FAT32 or exFAT - NTFS format is not readable. Also important, if you bought a UHS-I card (for example, U3), it will work slower due to the limitations of the memory controller in the smartphone.
Which memory cards are compatible with Xiaomi Redmi 9A?
Not all microSDs are equally useful. Three things are critical for the Redmi 9A:
- 🔹 Volume: officially supported cards up to 512 GB, but in practice it is better to choose 64-256 GB (class) A1 or A2) — They are optimized for smartphones.
- 🔹 File system format: FAT32 (up to 32 GB or exFAT (64 GB). NTFS readless!
- 🔹 Speed: Minimum Class 10 (10MB/s), but for recording video in Full HD better UHS-I U1 (30 MB/s).
⚠️ Note: MicroSDHC (up to 32 GB) and microSDXC (up to 64 GB) are the same, but Redmi cards are the same. 9A may not recognize SDXC, If it's formatted in exFAT on a PC, always format the card directly on your phone after you first connect.
| Parameter | Recommended value | What happens if you ignore it? |
|---|---|---|
| Class speed | Class 10 or UHS-I U1 | Lags when recording video, slow downloading applications |
| File system | exFAT (for cards >32 GB) | The phone will offer to format the card, lost data |
| Brand | SanDisk Ultra, Samsung EVO, Kingston Canvas | Cheap no-name cards often fly off after a few entries |
Step-by-step: how to insert and configure a memory card
Before you insert a microSD, make sure that:
- 📱 Phone is off (not necessary, but recommended for contact safety).
- 🔋 Battery charge greater than 20% – if the phone turns off during formatting, the card may be damaged.
- 🛠️ There is a paper clip on hand to extract the tray (goes complete with Redmi) 9A).
Follow the algorithm further:
- Insert the map: Find a tray for SIM-● Slip the paperclip into the hole and gently pull the tray out. Put the microSD in the microSD slot (usually signed as SD or TF). At Redmi. 9A Hybrid slot is supported: either 2 SIM + microSD, or 1 SIM + microSD.
- Turn on the phone and wait for notifications SD-map discovered.
- Set up the map: Go to Settings → Memory → Memory Map. Choose Format as internal memory (if you want to expand the memory for applications) or Format as portable storage (if you need only for files).
☑️ Preparation of the memory card for work
⚠️ Note: If you choose internal memory, the card cannot be retrieved without losing data, it will become part of the system.
Formatting a card as an internal memory: pros and cons
The main advantage of this mode is the ability to install applications on the map, but there are pitfalls:
- ✅ Pluses: 📱 Expanding memory for applications (relevant if the built-in 32GB is full). 🔄 Automatically transferred part of system data (cache, updates).
- ❌ Cons: 🚫 The card cannot be removed without resetting (it will become "tied" to the phone). ⚠️ Application speeds can drop by 20–30% (microSD slower than the 5.1 eMMC internal memory). 🔄 After retrieving the map, the applications installed on it will cease to work.
The critical nuance for the Xiaomi Redmi 9A is that if you format the card as internal memory and then reset the phone to factory settings, the card will become unreadable. It will have to be formatted again with all the data lost.
💡
Before formatting the card as internal memory, copy all important files to the PC – the process erases all data without the possibility of recovery.
How to transfer applications to a memory card
Even after formatting the card as internal memory, the applications don't automatically migrate. Here's how to do it manually:
- Open Settings → Applications → Application Management.
- Select the app you want (such as WhatsApp or Google Maps).
- Press Warehouse. → Change. → choose SD-map.
- Confirm the transfer. The process may take a few minutes.
⚠️ Note: Not all applications support portability, such as system utilities (MIUI Security, Google Play Services and some games (PUBG Mobile, Genshin Impact) remain in internal memory, and after transferring the updates, applications can run slower.
| Type of application | Can I reschedule? | Effects of transfer |
|---|---|---|
| Social networks (VK, Telegram) | ✅ Yes. | Slower download of media files |
| Games (Clash of Clans) | ⚠️ Partially. | Lags when loading textures |
| System (MIUI Launcher) | ❌ No. | — |
💡
Only transfer applications that are not critical to speed (such as instant messengers or offline cards) to a memory card; games and heavy programs are better left in internal memory.
Frequent mistakes and their solutions
If the memory card is not identified or is not working correctly, check:
- 🔌 Contacts: Remove the card and wipe its contacts with a smooth (no pressing!) Dust or oxidation can disrupt the connection.
- 🛠️ Formatting: if the card was formatted on a PC in NTFS, The phone won't see it. Reformat to exFAT via Redmi. 9A.
- 🔋 Power: With low battery charge (15%), the phone may not recognize the card.
- 📱 Software failure: restart your phone. If it doesn't work, reset your settings to Settings. → System system → Resetting settings → Resetting network settings.
If the card is detected but gives an error Damaged SD-map:
- Connect it to the PC through the card reader.
- Run the command in cmd (on behalf of the administrator): chkdsk E: /f (replace E: with the letter of your drive).
- If it doesn’t help, format the card in exFAT via the SD Formatter utility (download from the official website of the SD Association).
What to do if your phone is writing "SD-card protected from recording"
How to safely remove a memory card
While the Redmi 9A doesn’t have a “safe extraction” feature (like on PC), stick to the rules:
- Close all applications that may use the card (gallery, music player, file manager).
- Go to Settings → Memory → Memory Map and click Extract (if the card is used as portable storage).
- If the card is an internal memory, transfer all data back to internal memory first, then reset to Settings → Memory → Memory Map → Data Transfer → Internal memory.
- Only then do you physically remove the card.
⚠️ Note: If you remove a card formatted as internal memory without first transferring data, the phone may freeze the next boot. -hard reset (squeeze power supply) + Loudness up on 10 seconds).