So in my infinite wisdom, I had planned to relocate the master on/off/combine battery switch aft, near the circuit panel, while the battery banks are just forward of the keel. It seemed like it would make sense, keep everything together.
Then I priced the battery cables. Lets see, I need to go from each battery positive terminal to the switch, then from the switch back to the starter, then a negative back to the batteries... About 80 feet of cable, carrying starter current. Thats only about $700 in cable!
I guess I'll leave the master switch right where it is, about 3 feet from the batteries. Its hard to get to but at least I can afford it!
But then I have to get from the master switch to the panel. The PO used AWG 10. The panel has a 50A breaker. I don't think so. According to the formula in Casey's book, for 40 foot round trip at 50A I'll need AWG2. That's about $75.
Any way can save on this? The only thing I can think is that I could run the positive to the panel, but then see if I can find something to ground the panel to, since the batteries will be connected to the inboard engine block. If I do that, will I need to worry about electrolysis?
Any other ideas? Did I do my math wrong?