Hello Olivier and all. Thank you for your answer. My boat is the Santorin no.122.The new charger is Sterling pro-charge N. This replaces the original TECSUP of AMEL. I do not know if this new charger should have the carcass to the ground connection, or not. And if so where I would connect the ground screw?? Sorry, but I do not remember if and where it was connected the TECSUP.Regards.