I am running a 12 volt power drive with an i-pilot on dual batteries, I would like to put my 768 up front and a 798 on the helm with an inter link. Now on to the questions can i wire both units to the trolling batteries or should I run them off the cranking battery? On that type of set up do u run both units off one gps receiver or a receiver for each unit. I was thinking if everything ran off the trolling batts I could leave both units on all day and not worry about having enough juice to crank the big motor. Does anyone see any problems with that set up, if so how would you guys rig it?