I remember Gerald J's comment about soldering.

http://talk.newagtalk.com/forums/thread-view.asp?tid=153327&posts=1#M1099560

Not sure if this translates to larger battery style cables or not or was directed more at smaller wiring and soldering.

I've seen some soldered and some not. Larger crimp on lugs for electrical panels /meter bases etc that I saw made seemed to have a grease in them and are crimped. Don't ever recall seeing those soldered at all.

Maybe Gerald J. will chime in and give us his informed opinion on the larger cables.

Edit: Looks like one of those lively Internet debates solder vs crimp.

Conclusion a good crimp or a good solder connection will probably both work and last a long time.

http://www.marinewireandcable.com/2013/11/crimping-vs-soldering-marine-cable-and.html

 http://www.jalopyjournal.com/forum/threads/making-battery-cables-crimp-or-solder.694236/

http://www.garagejournal.com/forum/showthread.php?t=258265