Here is the deal, I will be adding a system to my boat very soon. I currently have two batteries, 1 cranking, 1 deep cycle marine/RV battery (used for trolling motor). I want to install a perko switch and run all the stereo and amp stuff off the deep cycle. When installing the perko, can’t I just take the pos wire from the cranking battery and hook that into the comm. Also, do I really need to hook up the alternator f connect. Next issue, will I be able to use the deep cycle as my second battery or will I have to get another one. Won’t the engine charge the deep cycle when the switch is set to all and the boat is running? Thanks for your input in advance.

Forgot to mention that my boat is an 4.3L I/O, I shouldn't have to upgrade my altenator should I? I believe amp will be drawing roughly 56 amps, 75 amps peak

Here is a diagram<!--attachment: Boat_Set_Up-673720.pdf*mime_pdf.gif*application/pdf*67.8*Upload*Boat+Set+Up%2epdf --><center><table border=1><tr><td><img src="http://www.wakeworld.com/MB/Discus/icons/mime_pdf.gif" align=left alt="application/pdf">Upload<br><a href="http://www.wakeworld.com/MB/Discus/messages/65921/Boat_Set_Up-673720.pdf" target="_blank"><b>Boat Set Up.pdf</b></a> (67.8 k)</td></tr></table></center><!--/attachment-->