There are really three types of batteries in common use in boats. Your plain old automotive starting type which work fine in most applications. Next would be the deep cycle batteries that can withstand deep discharges that can occur running accessories such as stereos, trolling motors, refrigerators, etc. These are made for long/slow discharges and lack the high current for reliable starting. The third is a hybrid and generally labeled as a deep cycle marine starting battery. Each has its use and purpose, I like to use the hybrids, but occasionally they cannot provide the cranking amps to start my SBC when hot. Flipping and fixing cars/boats on the side, I generate about 50-60 waste batteries per year, I've not noticed that anyone in the inexpensive side performing significantly better than the others. Everyone has their flavor, but looking at the pile, it has a few of many brands. Figure about five years or so and you got your moneys worth. Take good care of them, don't let the auto type discharge too far, and I've seen some go 7 years. Optima's are a different construction and in a different class. You get what ya pay for. As for recycled batteries, they work great for projects your selling, but I've never seen one last over two years.
One more thing- A trolling motor on a Carlson should be considered Blasphemy.
