I like many on this list have decided to go with 4 six volt deep cycle batteries. I will add more if needed, but by the sounds of the postings here 4 will do the job. My questions is what are you using for battery boxes? I can find group 24, 27 and 4D, 8D boxes but don't see any that would hold 2 or 4 of the deep cycle six volts. I am installing Interstate brand, they are rated at 232 amp hours, just a bit more than the Trojan T105's at 225 amp hours but physical dimensions are the same. thanks for the input, Mike