Question on battery hookup

[bbjunkie7]

I have just installed new Optima Blue Marine batteries on my 2018 Flying Cloud. There is a black wire with a label "30 Amp Max" which I am unsure of where to connect it to.

Would someone who is expert in battery installation please advise me on which terminal to connect this wire to? I have all red wires attached to the positive terminals and all black ones attached to negative, but this last wire is a puzzle because it previously was attached a terminal the right side battery, however I believe this may have caused my batteries to fail sooner than they should have.

I have attached a pic, it is the black wire attached to the lower battery from the left side. It has a yellow tag on it and is attached to a terminal with two red wires.

thanks so much!, Tim

[Tyler2you]

Guessing it's either your trailer jack connection or the input from a Zamp solar port if you have one. See if your trailer jack works with it disconnected as a starting point.

It can go to any of the positive terminals on your batteries. However, I'd consider redoing your wiring a bit. It's best practice to have all of your loads (positive/red) connected to one battery and your negatives (black) to the other battery to promote balancing between cells. You may need a busbar/distribution block vs. cramming everything onto a single battery terminal if you go that route.