question

Bolt cutters work, shears if it has fine strands. You will need the right cable lugs (electrical or automotive suppliers). Can be soldered with resin core solder and a gas torch. Or yank the cable and take it to an auto sparky.

Or you could simply disconnect the cable and add a new short one between the shunt and the batteries...

@MrHappy @knownot @kevgermany , I finally figured out how to load a picture. OK, first, thank you all for responding. In the picture, the top battery has the HUGE negative lead on the post, going back to the system. You'll see the shunt in there, but it is not connected to anything. You see the 4 gauge wire on the screw post, that is coming in from the second battery below.

So @MrHappy are you saying that I disconnect the BIG negative cable off that post, and then "add a new short one between the shunt and the batteries". So I take a 4 gauge wire, attach one end to that smaller screw post, the other end to the shunt. But how do I connect the other side of the shunt, to that big fat cable that is disconnected? Some specialty connector?

Ok, I see. The lug on the end of the big negative cable is too small for the shunt. In this case, maybe cutting it and put two lugs of correct size on the ends for the shunt, as suggested, is the best choice. If the cable is easy to remove altogether, taking it to somebody who have the right tools as @knownot suggested is good, as it is important that the crimping is done correctly for safety resons.

/MrHappy

@MrHappy thank you. Unfortunately for me, the other end of that big negative cable is deep in the inside of the Airstream and I am not qualified to attempt removing it. I guess I'll have to hire a professional to come out to the storage site where I keep the Airstream. Thanks again.