coolbox

Hi everyone, hope all are well. So appears my 97 Elddis Alfresco doesn't have a charging unit. I assume it's previous owner removed it for some unknown reason. So my question... If I purchase this - https://smile.amazon.co.uk/dp/B016OP9WBC/ref=cm_sw_r_cp_apa_i_lJnnFbN9PN05C Do I simply use...