I recently bought an rv & replacing the roof with EPDM from Amazon then installing my 6- 225 watt panels. I've got 4 - 225 watt panel's on 4 Walmart deep cycle 122 ah batts as a 12 vdc system then I have 2 more 225 watt panel's set up as a 24 vdc system with 2 122 ah Walmart batts for the $800...