I won't even try to add to Rick, (damn that's good info Rick). But Chris, I do have to wonder why you keep burning up alternators. I suggest you have some other problem. Mainly in that the load you are asking your alternator
to supply is too big. This is not usually a Battery
bank issue, but more commonly an accesory ussue. Like lots of lights and other wizz bang features that when all on, are requiring a load in excess of what your alternator is able to supply. If you load is say 80Amps and you have a 65Amp alternator, you would need to look at fitting a 150A alternator for instance.