The battery would need to meet Mercury's specs because I'll be using it to start/run my Mercury PROXS 200 4s. I'll also run all accessories off this battery including my two Lowrance HDS 9" and a Lowrance HDS Live 12" with ActiveTarget 2.
What size (capacity) Lithium Ion battery would provide me with ample capacity to run these all day long, dawn to dusk? Most of the time I fish, I'd never need it for this long but I would for occasional fishing trips.