School me on a starting battery
Northen Batteries is located in Madison Wis and actually makes (most of the batteries out there - there web page shows them). They are very easy to work with and nice people who know what they are talking about.
That's what I would do if I were you.
Good luck and have a good day
AGM (sealed) batteries can generally tolerate the higher voltage, so if I were to make a recommendation for someone with a smaller (<100Hp) motor and only 1 battery, make it an AGM type.
The only reason for the high CCA rating requirement of some motors is the very poor starting efficiency. There is no good reason a marine motor should need the same CCA as your car's battery, since nobody tries to start their outboard when it is -20F.
So, for the record, Fishing Bum is pretty much correct.
BSEE UW-Madison '83, and charging industrial lead-acid batteries since '95 or so...