Marine/RV Battery
Which to buy, Costco Interstate or Walmart Everstart?
Forum Discussion
You only need the second 12v if they have power failures that last longer than your one 12v would. Otherwise you are mostly on the converter for 12v, and the one 12v is for the trailer breakaway requirement and for short duration power failures. (You can run the jacks etc setting up by leaving the 7-pin connected and engine on if a Ford)
