[RussWhite]

I knew my EE friend would help me understand the issue and thanks for the free education. I would like to fuse my starting batteries, but would they too use a 300 amp fuse since there are fewer batteries? If not what amperage should I get?

Steve,

I will have to do some reserach before I could answer your "how big is big enough" question. I can tell you right now, 300 is not big enough. Sizing the fuse is determined by the capacity of the wires and the draw of the load. In the case of our units, the number and size of the batteries is not much of a factor. We have more batteries in the coach side of things so we can supply lower amounts of current to our loads for a long time. However, on the chassis batteries, their job is to supply lots of current to that huge starter for hopefully a very short time. I do not have the specs on that starter readily at hand. This is a tough application because you don't want that fuse to blow while trying to turn the starter, just if the cable faults. My wild guess would be a fuse in excess of 1000 amps would be required. Interesting question... Russ