We are finishing up our RV-10 build. We decided to go with the 2 earth x batteries and a back up alternator. My question is on start up and flight do you turn both batteries on and in-flight do you leave on both alternators?
I have two batteries and 2 alternator (one is a generator)
Both batteries on for starting. If you have two batteries you might as well take advantage of the situation and give your starter all the juice it wants.
Like the other posters have mentioned, I can start it on one battery or both.
Same for the alternators, they are both on at all times and the back up unit will start generating if the bus voltage drops below 13V.