After a day of researching batteries, I think the only thing you need
to know is to put AGM batteries in your boat. They will work charging
off standard alternator / voltage regulator combinations, unlike gel
batteries.

More expensive but I think you have to have a really good reason to
carry a gallon or more of liquid sulfuric acid around in your boat.

According to Calder, wet cells have longer life and better performance
but only with a degree of care and feeding that isn't probable on most
boats. The real life mileage of gel's and AGM's is greater because
they are more tolerant of the abusive cycles inherent in most marine
applications.

I just went to give my spare aircraft battery its periodic maintenance
charge. I just moved it to the edge of the shelf in the small room
where I keep it and the phone rang. I realized a half hour later that
my eyes burned and my fingers itched. Just the fumes of a battery
sitting there are corrosive. It boiled over slightly the last time I
charged it and I didn't notice. Two months later, the residue could
make me feel that way. Think of that stuff in your boat.

The only way I could justify wet cells now would be a long distance
cruiser that needs technology available anywhere, can spend a lot of
time maintaining them, and needs maximum performance. If you must go
wet, vent the battery box so the air flow is completely separate from
the interior of the boat.

--

Roger Long



"engsol" wrote in message
...
On Tue, 15 Mar 2005 20:51:49 GMT, "Roger Long"
wrote:

While picking people's brains about batteries today, I learned why I
haven't
seen a friend of mine around the waterfront in a while. He isn't in
Florida.
He was bending over the battery in his boat a couple months ago when
it blew
up for no apparent cause. In addition to acid burns, the force of
the
explosion threw him against the bulkhead of his boat so hard that he
broke
ribs and punctured his lungs. He's been laid up for weeks.

I don't think wet cells have any place on a boat except maybe one
that
is
large enough to have a dedicated battery compartment.


Any further details? I'm just finishing the battery box on
my boat, and maybe there's something I need to know.
Hope your friend recovers soon.
Norm B