G510 hidden battery frame

Hello, I'd like to know more about the beautiful battery mounted by these bikes from Frey / Sobowo / Flx

This special battery is declared 17.5 Ah and 48V or 52V

I'd like to know more because I can't find battery pictures and specs over the internet.
Here below the example bikes. In my opinion the downtube is the same, and probably same producer.
Thanks / Regards

Battery porn?

I think the Frey battery is 13S6P, 78 Samsung 3500 cells, but it looks like they have a 5P version as well.