ACA-i21 Manual | Step-by-step User Guide

The ACA-i21 earbuds come with specs such as around 6 hours of battery life on a single charge, the dust and sweat-proof IPX4 certification, Bluetooth 5.3 with 10 meters of working range, SBC and AAC audio codec support, only 2.5 hours of charging time, and much more. Learn how to use these earbuds using this ACA-i21 manual!

If you are interested in purchasing these earbuds, you can easily do it using the Amazon online store. Also, in case you are interested in giving the original manual a look, you can do it here.

ACA-i21 Specs Sheet

Model	ACA-i21
Weight	Earbuds and charging case: Around 47.5 grams
Waterproof/IP ratings	IPX4
Bluetooth version	V5.0
Range/Distance	10 meters
Connectivity Port/Charging Cable	Type-C
Audio Decoding	SBC, AAC
Driver	12mm
Speaker frequency response	20Hz – 20kHz
Battery Life	Earbuds: Around 6 hours Charging case: Around 18 hours
Charging Time	Earbuds: Around 2.5 hours Charging case: Around 2.5 hours
App Support	No
Controls/Features	Play and pause a song, play the next and previous song, answer, end, and reject a call, voice assistant, Game mode
Accessories	Charging case, USB cable, user manual, ear tips
Price	Around 25 USD

ACA-i21 Accessories

The earbuds come with the following accessories:

• Charging case.
• USB cable.
• User manual.
• Ear tips.

ACA-i21 Manual | Pairing & Charging Guide

How To Control These Earbuds?

NOTE: The touch button is placed on the upper part of the body of the earbuds.

• Play and pause a song: Press the touch button on any of the earbuds two times.
• Play the next song: Press and hold the touch button on the right earbud for about 1 second.
• Play the previous song: Press and hold the touch button on the left earbud for about 1 second.
• Answer an incoming call: Press the touch button on any of the earbuds two times.
• End a current call: Press the touch button on any of the earbuds two times.
• Reject an incoming call: Press and hold the touch button on any of the earbuds for about 1 second.
• Activate the voice assistant: Press the touch button on the left earbud three times.
• Activate the Game mode: Press the touch button on the right earbud three times.

How To Reset The Earbuds?

Step 1: With the earbuds inside of the case, press and hold the button on the case for about 5 seconds, or until a white and red light flashes three times.

This will reset the earbuds.

How To Charge The Earbuds?

Earbuds

To charge the earbuds, all you have to do is place them into the charging case and close its lid. The earbuds will start charging automatically.

Charging Case

To charge the charging case, all you have to do is connect the case to a USB charger or charging port. It will start charging automatically.

What Do The Lights Mean?

Charging Case

• A red light flashes while charging: The case is charging.
• Said light turns off while charging: The case is fully charged.
• A white and red light flashes three times: The earbuds are resetting.

How To Pair The Earbuds?

To Android And iOS Devices

Step 1: Open the lid of the charging case. After that, the earbuds will turn on automatically and pair with each other.

The earbuds will now be ready to pair with any device.

Step 2: Unlock the desired device.

Step 3: Go to the device’s settings.

Step 4: Turn on Bluetooth on the desired device.

Step 5: Search for a new device.

Step 6: Select the ACA-i21 earbuds. If a password is needed, type “0000” or “1234”.

After that, the pairing will be done.

To Windows (PC)

Step 1: Turn on the Window’s Bluetooth.

Step 2: Go to the settings.

Step 3: Go to “Bluetooth and other devices”.

Step 4: Click on “Add device”.

Step 5: Click on Bluetooth.

Step 6: Open the lid of the charging case. After that, the earbuds will turn on automatically and pair with each other.

The earbuds will now be ready to pair with any device.

Step 7: Select the ACA-i21 earbuds. If a password is needed, type “0000” or “1234”.

After that, the pairing will be done.

How To Wear These Earbuds?

Step 1: Take both earbuds out of the charging case.

Step 2: Identify the left and right earbuds.

Step 3: Choose the ear tips that best suit your ears.

Step 4: Insert the headphones into the inner canal of the ears.

Step 5: Rotate for the best possible comfort and best fit, and make sure that the microphone is pointing to the mouth.

How To Turn On And Off?

Turn On

Automatically: Open the lid of the charging case. After that, the earbuds will turn on automatically.

Turn Off

Automatically: Place the earbuds into the charging case and close its lid. After that, the earbuds will turn off automatically.

Do These Earbuds Have An App?

No, these earbuds don’t come with app support.

Some Common Problems & Troubleshooting

Left/Right/One side of the earbuds has stopped working

If this happens, it may be because it is low on battery or it did not connect correctly with the device. To fix this, you can do the following:

1. Try charging the earbud that is not working or both, placing them in the charging case.

2. Try factory resetting the earbuds.

3. Check if the earbuds are operating within a normal working range.

If that doesn’t work, the earbud is probably faulty, and I can go for a refund or replacement of it.

Left/Right/One side of the earbuds has a low volume

If this happens, it may be because the earbuds are dirty or the volume is set low. To fix this, you can do the following:

1. Try cleaning the earbud using a cotton swab or carefully clean the mesh with a pin.

2. Try factory resetting the earbuds.

The microphone is not working

If this happens, it can be because the microphone is muted, or the earbuds are badly positioned. To fix this, you can do the following:

If the microphone is muted, check the device microphone volume. If that doesn’t work, that means that there might be a defect in the earbuds, so try replacing them or getting a refund.

The earbuds are not connecting to Windows/laptop/PC

If the earbuds are not connecting, it can be because the Bluetooth on the computer has a pairing problem. To fix this, you can do the following:

1. Try disabling Bluetooth from nearby devices >>> then activate the pairing mode of the earbuds, pair and connect earbuds from Settings >>> Bluetooth & other devices >>> Add a new device >>>> Select Bluetooth.

2. Try uninstalling and reinstalling the Bluetooth driver, or updating the Bluetooth driver. All can be done in Manage >>> Device Manager, reset earbuds (if available), and then repeat the step.

3. Try resetting the earbuds.

FAQs

We hope you now know how to operate the earbuds from the above ACA-i21 manual. Want to know anything about the earphones? Do not hesitate to ask in the comment section below.