Can anyone tell me how to find the internal serial number on my Dji Smart Batteries for the Mavic 2 Pro?

There u go! its located on the battery with the qr code

That's the external one, there's also an internal..

Boominshot Posted at 3-25 01:18
That's the external one, there's also an internal..

If you have an Airdata account, upload your flight logs and there you are:

Use FRAP and it's shows you the nr
https://forum.dji.com/forum.php?mod=viewthread&tid=145649

Hi, thanks for the inquiry. We're sorry that you don't have a serial number for the internal battery of our DJI Smart Controller, however, we would like to know how can we assist you in regards to this query? Please keep us posted for further assistance.