I am starting an SS7 build soon which will include the EP915ti engine.
I'm looking at the power requirements for everything onboard and am
using the following numbers:
power.jpeg
My mission is day/night VFR only. I'm planning on using the Vertical Power VP-X and PPS.
I plan on a single power bus.

The 914 has an internal alternator that produces 18 amps so obviously not sufficient to run
everything at once. I've been looking at the Edge Performance 32a Alternator add-on but
that's still not quite enough.

Here are my questions:
1) Do I need an alternator that can handle the entire maximum load? (my guess is no since some
items are intermittent like radio xmit and trim motor)
2) How do I figure out exactly what size alternator I need?
3) Based on the load requirements will I need to make the add-on alternator the primary and use
the 914 internal alternator as the backup?
4) Do I even need a backup alternator since the battery can carry the load if the add-on alternator
fails? I'm assuming if the primary fails the system just runs on the battery and the engine will
continue running for some period of time based on what electrical components are still on and
the battery capacity. My goal would be 30 mins of flying + G3x PFD running and no radio.

Victor