High current diodes are great, in theory, and will keep current flowing in the
correct direction.  But they have a problem when it comes to 12V multi-battery
charging systems.  That is, the forward voltage drop will likely be over a
volt, depending upon actual current.  How do you compensate for that?

//Jack

Date sent:              Wed, 21 Feb 2007 18:49:34 -0700
From:                   David Etter <detter@MAIL.AURACOM.COM>

> If the main battery was depleted, having my aux. battery on a 10ga.
> wire from the alternator with an inline 50amp diode prevents the aux
> battery backing up into the main battery through the alternator
> connection. Thus you will not ruin the aux. battery attempting to
> equalize the depleted Main.