I guess, you would have to find out what the amperage draw of the winch/compressor...since these two items are probably the largest draw besides the starter.

A starter normally draws about 200/250 amps at initial contact, then goes to about 120/160 as things get moving, then rises as heat within the starter motor becomes a factor. Now, these are rough estimates...since all engine, drive trains are different in friction/resistances. I'd assume that a winch, with all of the resistance invoked, would draw considerably more.

Anyhow, what you are trying to do with your higher amperage alternator...is help assist the battery. The battery will be handling the majority of the battle (draw) throughout. This is why I suggested a larger diameter cable; more amperage available to the battery from the alternator. Let's say your winch is drawing 450 amps during initial use, and the CCA of your dual battery system is 2000 amps. A system like this should maintain a 50 percent draw for so many minutes (1000 amps), without help from the alternator (engine off). But, with the aid of an alternator...that time increases considerably...since you are assisting the batteries in battle. Eventually, you'd probably want to let the alternator "catch up" during a substantial pull.

Again, this is why I suggested installing the larger cable to your battery...in essences...it is supplying a larger path, where more amperage can/needs to travel. You do not need a circuit breaker as long as your cables are routed properly and shielded. Your starter cable from the factory doesn't have a circuit breaker.

Brian.