Battery charger from LIDL for external socket

Hello first of all, with the politically questionable discounter Lidl there is an extremely cheap battery charger.http://www.lidl.de/…/c.o.20080128.p.Battery charger.ar31 My question: Can I clamp the part in my camper (Fiat Scudo) behind the external socket to charge the supply battery 110A and the starter battery at the campsite on the one hand? I am sure that there are a lot of arguments from camping aesthetics that speak against it, but the whole is a student r Low Budget Van. a 20€ Baterie Separation Relay has already won me 🙂 So what do you think, technically possible? Thank you very much! Mazrael