Shaun Simpkins wrote:
> But we still have to contend with 6-8A drain for position/nav lights and
> 4-7A drain for strobes.
> So for night flight, we'd need to add the SD-8 and call it the "night
> alternator"...
Those lights are a problem. But an approved, single strobe (vertical
fin) can get you well under 4A. For position lights, the "Grimes"
lamp is showing me < 2 amp each, and a tail item is less. But I'm
still experimenting with halogen lamps, to see what can be done to
save amps. Technically they need to be a "approved" also, but I doubt
the inspection will include what's hiding inside the lens. I also put
a little halogen inside a tiny, actual Grimes white running light or
whatever it is, attached to a fairing on the (lower) trailing edge of
the rudder. That also avoids the drain of two white lights in the
rear of wingtip strobe/position lights.
> This leaves the 20AH/12 RG battery at 15.3 lbs as the energy density
> champ. 300CCA min, -20C, 30 sec.
That sounds pretty good, but there's a curious footnote on their
"dimensions" page for this battery. Short circuit is 1,200 amps, 2/3
of the lighter Odyssey PC625, suggesting it has a higher internal
resistance. Hawker Energy (Odyssey) publishes the discharge curve in
a 77F cranking amps test, and it would be curious to compare the two
to see what each delivers in the first 5 and 10 seconds. That's like
actually starting an engine in more realistic weather, and where
internal resistance hurts the most. They may be at least equivalent
there, and one could save a couple more pounds.
Regards,
Fred F.
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