> I thought the whole gel idea was to prevent battery acid leaking out if the
> battery (boat?!?) upended.
>
> Your thoughts?
>
It depends on your preference for risk vs. expense.
Lots of people are perfectly happy with flood marine batteries. And you can
buy two of them for the price of one gel or AGM battery.
The West catalog has a very useful "advisor" in the electrical section. You
can read it or point your web browser to the West Marine on-line advisor.
I have a horror of battery acid, so I bought a Concorde AGM battery, which
costs about the same as a gel battery, but is newer (perhaps less proven)
technology.
One advantage to both gel and AGM batteries is that they lose only three
percent of charge per month while in storage, which is alot better than flood
batteries. We store our boat where there's no way to charge it so that's a
plus. We use the battery very sparingly and there's a charge indicator on our
battery box for monitoring it. We take it home periodically to charge it.
One reason we chose the AGM over the Gel is that you get more amphours (95 AH)
in the size 27 than the gel battery (86) for about the same weight. We had to
stay under 65 pounds so I lift it and move it by myself if necessary. Even
so, it's damned heavy. West's Flood batteries give you the most AH per pound,
but you better not drop them....
AGM: size 27, 63 lbs, 95 AH
Gel: size 27, 64 lbs, 86 AH
Flood, size 27, 52 lbs, 105 HA
Third, an AGM is submersible without damage.
One disadvantage to both gel and AGM batteries is that you need to have a
"smart" battery charger to avoid damaging them by overcharging. It you
overcharge them, the damage is permanent. I bought a True-Charge 10A two-bank
charger from West Marine.
Judy Blumhorst, DC
WWP-19 #266 "Red Wing"
SF Bay, CA