I'm replacing my OEM 4Ds after 7 years-5 with PO and 2 with me. One has failed and the other is probably not too far behind. I've settled on 2 pair of 6 volt, like the Trojan T105. My question is the size of cable to put the pair in series. The boat's battery cables are 1/0 guage. Do I need it that large to run 6 or 8 inches between the + and - posts? Seems like 2 or 4 guage should be well sufficient based on the charts, but your opinions and experience would be greatly appreciated.