Re: Electrical Upgrades
Mostly I wanted to say nice diagram. Visio I assume?
Then, second I'd add that I agree with the feedback above. The Echo is designed to only turn on when it sees charging voltage and is designed not to drain your house bank. Also you should just wire the alt directly to the house. 1) This guarantees you're charging both batteries all the time your engine is running 2) You can never flip the switch off and risk burning out your regulator (although if you're buying a new one you could read up and confirm if this is a problem).
I'm not familiar with shore power systems but the same reasoning seems to apply and I suspect those systems as well are designed to not drain the battery when AC power isn't present.