Right, I understand the basics that it is affected by equipment ratings, however, I would imagine there is some "standard" that is used. And I'm with you, I have only seen a few 3 batt systems, it seems like people running more than 2 go straight from 2 to 6 or some crazy number. I'm not needing all that. Also, I have a Pro Mariner dual bank charger that gets plugged in every time the boat comes off the water, so as far as after use and recharge once the day is done, that's covered (although once we get some replies going I already have a question about this as well). I'm looking for a full day on the water situation. Make sense?