The prius hybrid batteries have been having cronic issues with the copper buss bars between modules getting corroded by Potasium Hydroxide weeping through the terminal seals. The effect is a crust of hard material that is non conductive, eventually causing battery failure.
I want to build up more of the 48V modules for my EV's, and wanted to find a way to clean the strips more efficiently than sanding and using steel wool, which can take as much as several minutes of hard work each.
I remembered my Dad showing me how to make old copper pennies shine buy dunking them in muriatic acid (Hydrochloric acid). I still had a container of the stuff which can be bought at most hardware stores, so I gave it a try. It immediately causes the crust to dissolve in a flory of bubbles, and then it stops, and the strip is mostly shiny copper. A thorough wash in running water finishes the job by washing off all the acid. Time will tell as to how it look a year from now, but it looks good now.