Importance of Battery Positive and Ground Wire Upgrade

For your standard output alternator and standard system you do not need a larger
battery wire. But if you are using your alternator to it's maximum output or when you
upgrade to a higher output Alternator you must increase the wires size. An alternators
ability to send the power it is making to the battery is directly related to the wire size
between the alternator and battery. Also, a small a wire on a high output alternator can
cause the power to back up within the alternator causing it to overheat or burn up and
fail. Another area that little is paid attention to is the ground. You must also improve
the ground as well. A poor ground will hinder the alternators ability send power to
the battery and can burn an alternator up just as fast as an inadequate battery wire.

Alternatorman