which battery is good for your boat ?

[harrymaan]

Dual purpose or Deep cycle battery?

 

[WalkIntoTheLight]

If you're sticking with SLA, I wouldn't use anything other than deep cycle. It can provide high enough cranking amps when you need it, and you're not going to be boating in -20 degrees when the CCA might not be enough.

 

[Timothybil]

Are we talking about a 'start the engine, power some accessories' battery, or a trolling motor battery? Completely different profiles involved.
If it is a 'start the engine' battery, is it one or more outboards, or an inboard?