Jzeveney,
Verify this, Code requires the interfacing connection to be of the same material to prevent galvanic corrosion. Assumption is the terminals are lead, so the copper needs to be lead coated at the battery interface. (only required at the ends)
Even if code is not a worry, the issue makes since to lead coat the copper.
Insulate the bus bars, heat shrink tubing will do nicely.
I found some clear shirk tubing with mastic supposed to seal better.
Will polish the bars and tin ends. After I drill bolt hole.
Should look nice for a while!
My first copper was cylinder 5/16, planed to flatten ends.
Took 45 minutes to cold form the spade lug on both ends. And a sore arm.
Then bought 0.375 x 0.75 inch bars. Was too thick, should have gotten 0.25 max.
Had to drill out the nut area 0.125 inch.
Make sure to leave spacing between each battery, they swell with age. Quarter of an inch should be good (for golf cart, more for larger battery).
Battery pack is 48 volts, 8 golf cart batteries. Connected U shape with fuse in middle of string.
Have fun,
Scott.