Thinking about changing my 3 year old battery before the season starts should you buy a deep cycle battery like boats use since it is recharged all the time or any good battery ok?
No matter where you buy it Marine batteries will be sized by "Group" number get the highest Group number you can fit. A group 31 would do well and last a long time. The higher the group number (in the Auto sized type batts) the more reserve power the battery will have.
You can get decent Marine Batteries at almost any big auto store like NAPA. Or Sears.