I see this as an absolute win. Be careful, folks. Just because it’s DC doesn’t mean it won’t cause serious damage.
Edit for Clarification: When done correctly, the batteries should not arc. My problem is I did not wire the array correctly the first and a-hem second times. It only cost me one battery, which is a lot cheaper than a trip to an American ER.
It was the former. This unit had 8 12v batteries VERY snuggly placed within it. I didn’t pay attention to all the leads and their locations when dissembling the old batteries. I’m professional IT and hubris was nearly the end of me.