I have a 2010 shamrock 21s. We camp at a place where there is no electric hook up and you can only run a generator 8am-11am and 4pm- 6pm. I want to replace the two batteries i have with the largest 2 12v deep cycles on the market. They are not hooked up together. i use one at a time. When one runs low i hook the other up and charge the other with a e2000 honda generator for two hours. does anyone have any input on the best deep cycle batteries available?