The voltage drop is maybe 1 volt. Some warming may occur on the wire run as this increases resistance and doesn't create a problem as long as the wire is rated for the amp load. The main idea is to locate the batteries farther away from the alternator
. The fools the alternator regulator
. The regulator
is looking at the output terminal
and regulating from there. Adding a length of wire limits the amperage draw on the alternator. Think of it as the same as using jumper cables
This idea is useful in a situation where a real small alternator is running a large battery
or bank of batteries.
Although a coil of wire presents a magnetic field and one would use canceling loops to stay away from interference
to AP compass
and all that.