Power/Battery Question

[Basscalade510]

I am running a 12v terrova trolling motor, helix 7 on the bow and helix 5 in the console, and of course the livewell. I am constantly having to turn off depth finders just to save power. If i want to add juice to my accessories and trolling motor would I want to add another deep cycle or cranking battery? Or both?

thanks