All of my high current DC cabling uses the ring terminal connectors...
This is perfect for using products like BLUE SEA Terminal lugs, HD Switches, FUSE Blocks, BUS Bars, etc...
Most of my cabling is 2AWG and 4AWG around the battery terminals...
I really observe equal cable lengths and all so that when being charged all of my connected batteries work together.
Check out BLUE SEA DC products on google search...
I do have a smaller battery bank in the bed of my truck which I use one of those 2-pin 4AWG cable connectors (ETRAILER.com) like your post shows. This allows me to supplement my trailer battery bank but I have a big problem trying to keep my batteries all charged together. I have to use separate DC charging setups to get both battery banks charged up in a quick three hour charge time.
You best plan IMO would be to have your two batteries mounted together inside the same battery box location. I found out using the same DC charger for both battery backs my worse case batteries always drained down the better batteries to the older battery performance...
Of course we all have our different defined install problems. Its all about what works best for you...
Roy Ken
