DPDT Switch for Battery Bank

Thanks everyone. I just installed the 1/off/2 battery bank switch. I ran 4/0 wire for #1 to the 2-6V battery bank, and 4/0 for #2 to the original tongue battery (12V). Same for the common to the original tongue batter connection at a inline circuit breaker underneath the trailer. Seems a little small for the connectors. Original wire looks like only #8 to the distribution panel. Took reading off the battery remote metering. Loads are a lot less then the fusing in the 12V distribution panel. So I am now set up to run 110V shore power with converter to supply 12v and charge tongue battery or 12V from tongue or 6V bank (converter and mains off). Should I replace the inline circuit breaker with a larger one. Can't make out the size. All in all the amsolar supplied equipment works well. Just wish there was a less complicated information guide for the remote. Thanks again.