I got it from here:
https://de.aliexpress.com/item/1005004417934706.html
I bought this charger because it is very universal and easy to setup. The max. solar voltage is 230VDC and battery between 12V and 96V. In the menu it's possible to choose the battery type, Lead Acid, GEL, LiFePo4, Li-Ion and User - and how many batteries in series.
It has a RS485 port - On the pictures it looks like a normal RJ45 network port but I was surprised to find out that it's a RJ12 6P6C (not included)
The settings for the port is: 2400 baud, check bit NONE, data bit 8, stop bit 1
If I send 0x01 0x03 0x00 0x00 0x00 0x14 0x45 0xc5 then I get 45 bits back, the string contains all registers