What battery size cable do I have?

[Sniper]

Well, industrial electrical expert I am not.  By training I am an electronics technician.  But I have worked in the field long enough to have picked up a lot of electrician knowledge, no they are not the same and I make no claim to be an electrician.  When I put a connector one a wire I prefer a crimp for mechanical strength and I also solder it for the best electrical contact, then use proper strain relief so that the wire doesn't flex and break.  That is how I was taught.  It could probably be done with cables that big, but it's not usually.  So if the OP has an electrician friend that can crimp them properly that's good.  But remember i was taught by the Navy, so our connections had to be adequate for combat, vibration, water intrusion, ect.  Something an electrician doesn't normally deal with.