Didn't see that article, but seems that Kitplanes is leading builders
down the garden path. Piper once used alum cable to an aft-mounted
battery, but few now have not been replaced with copper. The galvanic
corrosion between the ring connector and wire strands is inevitable,
greatly increasing resistance. Aluminum strip glassed to the
composite would have problems at the connections, and seemingly one
could use cad-plated washers between the strip and ring connector.
But each mating surface is an ohmic connection, adding up to voltage
drop. If it still corrodes in service, it becomes an increasing
effective heating element.
A mere 25 milliohms at a connection would cause a voltage drops that
might not be noticed. Keep cranking a hard-starting engine, and you'd
be dissipating over 100W of heat in a small heat-dissipating area.
Much smaller than that of a 100W, metal finned resistor, which gets
very hot at its power rating if not heat sinked itself.
If memory serves, in WWII they had to use alum house wiring. Long
banned in building codes now, after local fire departments spotted a
trend....
Best,
Fred F.
Nigel Charles wrote:
>
> There was an article about copper v aluminium battery cables in Kitplanes
> some years back. Although aluminium has a slightly greater resistance it is
> possible to compensate by greater cross sectional area and still win out on
> overall weight. Also solid strips of it can be glassed into the sides of
> the fuselage if a long length is required making a neat installation. Make
> sure that there is adequate glass to ensure good insulation otherwise you
> could end up with a nasty electrical fire.
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