We plan our RV10 to be IFR; essentially G3X/GTN 650 plus a small Dynon. We think we want I alternator plus 2 batteries, 1 start and 1 domestic, something akin to what boats have. The idea would be to set up the avionics before engine start, but protected from spikes/surge. But we are still thinking how to achieve this in practice. Has anyone got a system like this? I have a Dynon D6 in a Eurofox and it says you can have it on through engine start, but I assume you cannot take such liberties with Garmin stuff. Also, is the standard Vans voltage regulator OK? We know someone who allegedly got a big over-volt and destroyed most of his Avionics, but I am not clear how that would happen.