"I'm replacing the battery cables on all the batteries. What would be the recommendation, soldered or crimped terminals?"
On Island Eagle, I ran A LOT of #2/0, #2 and #8 cable. Probably 200 lugs in all. Here's what I would do if I were you:
1) Do not even think of soldering. It's very hard to get a good solder job, and even if you can it will cause hard points. Plus it will burn the insulation.
2) Use high quality tinned lugs. Pico sells the exact same ones as Ancor, at half the price. Don't forget that you need to size the lugs to the studs as well as the wire.
3) You need a high-quality crimper. I used the Ancor hammer-style one for about a dozen crimps, but the quality of the crimps was marginal (and BTW, if you HAVE to use this, use a vise to squeeze it, not a c-clamp or hammer). You can usually borrow or rent a good crimper, or for a big job you can even buy one. Try your local pawn shops and used tool stores, you can sometimes get good deals. In my case I borrowed a great pair from a friend who was a linesman for the local utility. Also, better marine shops usually have one, and if you buy the wire from them they will sometimes let you borrow their crimper overnight.
4) You will also need a pair of high-quality large-diameter wire cutters. Get Greenlee Model 727. They will cost you about $50. Keep them in a safe place an DON'T use them to cut anything but copper cable.
5) Once the lugs are crimped on, cover them with adhesive-lined heat-shrink. You will need a good, hot heat gun to shrink this stuff, it's pretty hefty. This will ensure that the joint stays corrosion-free.
I found it easiest to cut all of the cable at once and then set up a bit of a production line to do all of the lugs.
One other hint, a lot of stores have random lengths of wire that have been miscut or are end-of-the-roll. You can often get a good deal. Remember, you can always go up in size. For example, I got 27 feet of black #3/0 for less than 25 feet of #2/0, just because the 3/0 was a misorder and had been sitting on the shelf for a year. So now I have #3/0 running to the starter instead of #2/0 :-)