Connect battery charging cable for CTEK charger permanently – where?

Hello together, since I own a battery charger from CTEK, which I like to hang on to the car on the WE times (in winter), I wanted to connect an adapter cable to the battery so that I don’t have to work with the crocodile terminals. I was now a bit “overburdened” : on the battery sits a black box, into which several cables go, or from which several cables come out. Does anyone have an idea how to get this box? I now have the adapter cable as shown in the photos. What do you think: Is that all right? So far I have always connected the adapter cables directly to the battery and that has always worked very well. But I can’t access the actual plus pole of the Seat battery. VG, Thilo