My airtag is not connecting with my phone after battery replacement

Hi Vsongs,

Thank you for posting in Apple Support Communities! Since replacing the battery, has the AirTag been reset? Resetting the AirTag will allow your to pair it with your device again.

According to this article: How to reset your AirTag - Apple Support you'll want to do the following to reset your AirTag:

1. Press down on the polished stainless steel battery cover of your AirTag and rotate counterclockwise until the cover stops rotating.

2. Remove the cover and the battery.*

3. Replace the battery.

4. Press down on the battery until you hear a sound. This sound means that the battery is connected. 

5. When the sound finishes, repeat the process four more times, removing and replacing the battery, then pressing down on the battery until you hear a sound. You should hear a sound each time you press on the battery, for a total of five sounds. The fifth sound is different from the previous four. This indicates that the AirTag is now ready to pair.

6. Replace the cover by aligning the three tabs on the cover with the three slots on your AirTag.

7. Press down on the cover.

8. Rotate the cover clockwise until it stops rotating.

Once reset, you can follow the steps in this article to set up your AirTag again: Set up your AirTag using your iPhone, iPad, or iPod touch - Apple Support.

Hope that helps!