I am writing this post because I was unable to find this information anywhere on the internet, and people likely want some help with the order of placing the batteries and cables into these empty units bought used.
Here are the steps in order!
1. tape the first two batteries together and attach them like so.
Then tape the second pair together and attach them as pictured
The third ones go back to back.
The fourth are the trickiest to get right, make sure the wiring is exactly as pictured.
Then you put in the last pair.