If you want to see an FAA-approved electrical system for an all-electric airplane, see the Columbia operator’s manual, available from Columbia Aircraft on line.  To save you the search, I printed, scanned, and attached the appropriate page.  There is a lot of wisdom embedded in this comparatively simple diagram.  When you see those big diodes, think of the low voltage drop Shotky diodes from Perehelion Designs.  “PFD” means “primary flight display.

Fred Moreno