Doug,

I have dual alternators and dual batteries per Aero-Electric Z-14 architecture.  I’m using the small 55amp ND units.  They weigh about half of what the Mazda alternator weighs, so I rationalized that there was very little weight penalty to using two alternators, but a significant safety improvement.  With an electrically dependent engine and all electric panel, I decided this was the way to go for me.  The cross-feed contactor connects both Odyssey batteries during starting, so I am able to use smaller batteries than would be required to start the 3-rotor with only one battery.  Every annual, I plan on replacing the main battery, rotating the 1 year old main battery to the aux position, and move the 2 year old aux battery to my Goldwing motorcycle.  That way the main battery will be less than one year old, the aux battery will be 1 - 2 years old, and the motorcycle battery will be 2-3 years old.  I’ll send you a picture off-line. 

 

Mark S.