vh2q wrote:I am thinking that the 12V battery voltage should not dip too much with the main battery "backing it up", ie with the ignition on. I just don't know how hard you can push it and for how long before the fuse blows. And I am pretty sure the fuse is 80A.
Yes according to the Schematics it's an 80 amp fuse, thanks for the correction.
The surge loads you mentioned are going to require some serious battery capacity to hold through without tripping the low voltage threshold on the inverter(s). I'm thinking about 500Ah, "trickle" charged by the iMiev through a 50 or 60 amp resettable DC circuit breaker. I've seen way to many backup systems that are pushed to close to upper limits and then when needed most, something fails. Leaving no power at all until repairs are made and expensive components replaced. Not much of a backup system if it fails when you need it most!!
For longer outages you simply must have some solar input to the batteries as well. Generators just bring your neighbors to your front door . . . extension cords in hand