I currently run a 16' Crestliner, it has a 2004 30hp 4stroke Johnson. I do a lot of trolling with it and run all of the accessories of my 27series crank battery (electric downriggers, sonar/gps, Sub Troll, VHF radio, ect..) These are all hardwired indivually (with inline fuses).
The house (lights, bilge, livewell) and motor came indpendently wired together.
Ive been running like this for a few seasons now with no issues but am considering adding a second (smaller) 12v battery for the trolling accessories. Is it neccessary?
If I choose to add a second battery, what would be the best way to go about doing it so that the alternator would charge both?