Pretty good battery terminal connectors-

Our host doesn't carry these things - perhaps they ought to consider it?

These seem much, much better than the "Walmart's Best" that I had been using. Brass is far more electrically connective than lead. Plus it is harder so you can really tighten the bolts down. 

Was going to post a link but the seller is a competitor so that might  be poor form. Here is a pic of my "brainstorm". This is not a perfect install, it is how I did it in 2014(?). Spent another $50 to add four more 8D's. Trying to supplement my batteries a bit. 
I don't like these 17mm and 19mm posts for solar batteries though. If that is what you have to work with:
(1) Use felt washers over the terminals to keep corrosive battery mist down.
(2) Spray a good battery terminal sealant over the connections.

A cut off wheel on a grinder works well for "sanding off" any difficult corrosion. Using the wheel sideways of course. 

This is an ongoing experiment that the purists throws a "thumbs down" on. We. Shall. See. Nobody is recommending this. An "experiment" of sorts. What may look like terminals next to steel posts is air gapped by at least 1".