>What size wire are people using for the main battery cable. I gotta
>get mine. Richard says his (#2) cable sometimes doesn't seem to
>"carry the load."
For airplanes where the battery is on or just behind
the firewall, 4AWG is fine for all the "fat" wires.
If the battery has to be further away, like on the
other end of the airplane from the engine, #2 is better.
I have dozens of Ez builders who have run 2 strands
of #2 full length of the airplane to crank an O-320.
4AWG is about .00025 ohms per foot. A 24 foot round
trip in an Ez is .006 ohms. A 200 amp cranking current
will drop 1.2 volts or about 12 to 15% of your total
cranking energy. 2AWG drops to .004 ohms total
for a voltage drop of 0.8 volts in the wire. Of
course each terminal joint and set of contactor
contacts will ADD to this resistance but our experience
has shown good performance for even the long circuits
just cited when 2AWG is used.
If someone is having difficulties with a 2AWG
wired starter, I strongly suspect a combination
of tired battery, high resistance joints or high
resistance contactors are the major contributors
to the problem. Some measurements with a
voltmeter while loading the system with an
automotive load-type battery tester will quickly
isolate the causes.
Bob . . .
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