Thanx much for all of the helpful tips. My current set-up uses 4 guage, but I was thinking that once I get my GC batteries and the new PD converter in there (when I get back home from this trip) I will start planning for an inverter (maybe a good size one to be ready for some short-term higher-drain use) so I thought that maybe it would be good to plan ahead for occassional higher-amperage load on the batteries. Based on the input here, I'm going for the 2 gauge. With the suggestion above and Amazon Prime I'll have one waiting when I get home Friday with the new batteries...