Hi, I have in my Lund a circuit block connected to my cranking battery. I wish to connect my new sonar to a dedicated RV battery that is also connected in parallel to the cranking battery thru the circuit block. I am trying to have my Hondas first charge my cranking battery and then because I am using a parallel circuit charge the RV battery. Again the circuit block would be where I would connect (start) the parallel circuit. Now the question is where I should locate an isolator in the circuit to the RV battery? Should the inline isolator be close to the RV battery near the bow OR should the isolator originate at the stern after the circuit block at the beginning of the parallel circuit? I hope my request for assistance makes sense. Thanks Jim