Quote Originally Posted by timbo 66 View Post
I need to purchase a new cranking battery, my question is what is a dual pourpose battery? Can I buy a deep cycle and use it for a cranking battery or is that what the dual pourpose means. Also what do you all recomend as far as what make of battery. Thanks guys.
If the battery has enough CCA for your motor, you can use it whether it's labelled as cranking, deep-cycle or dual purpose.

Deep cycle batteries have a moderate number thick plates to stand up to the constant deep discharge. Cranking batteries have a large number of thinner plates to allow for high current. Larger deep cycles typically have enough CCA for many motors up to 150HP or even more if they aren't HPDIs. A deep cycle or DP as a cranking battery is often the best choice if you run livewell pumps and a lot of electronics.