GL: AGM Batteries

[Bob Austin]

Sometimes postings can be a bit confusing to people who are not experienced.
Although AGM batteries can be put upside down, this is not recommended by any
of the manufacturers.  The best feature is that if a boat rolls, the batteries
will still be OK.

As far as depth of discharge--if you repeately discharge fully any type of
battery it will shorten its life.  There is always a compromise between
longivity and depth of discharge.  The best practices is to not discharge a
battery more than 50%--yes, it will tolerate an 80% discharge--but the deeper
the discharge, the shorter the life span will be.

For the average boater, who maintains his batteries well, adds water, keeps
them charged, and keeps them clean , keeps them in ventillated places and does
not abuse them by excessive cycling--the standard lead acid batteries are
still the best value.  AGM generally cost2 to 3 times as much as comperable
lead acid.  My personal preference for lead acid batteries are golf cart
batteries.

Bob Austin