Another relatively low cost option for your cable ends (depending on strand size) is to tin them directly.
The majority of the 2/0 connections on the ForkenSwift were hammered relatively flat, then I wicked solder into them, making them solid. They were then ground flat & drilled for the battery post bolt.
DIY end top, OEM bottom:
I also tried the copper tube sheath approach, but it didn't work as easily:
For more info/details on how these were made, see starting around post # 406 in the ForkenSwift build thread, roughly here:
http://ecomodder.com/forum/hreshowth...3-post763.html
Several years later, they're still working fine (not getting hot or flattening out/creeping).