Gould,

Thanks for the good comments. I will consider if Group 27 will fit. I'm a
little
confused by the deep-cycle vs. dual use. If deep-cycle will be OK for
starting
then why ever buy/make a dual-use?


OTOH, you could afford to buy cheap batteries a few times for what you'd
spend
for Rolls or Surette. Pay now, or pay later.......but if you only intend
to
keep the boat a year or two before trading up the average quality cheapies
are
probably the way to go.


We've worked 2.5 years on this boat. We've got more into her than they sell
for.
It was a labor of love and I expect that I'll keep that boat until I'm dead.
The memories
of my father shaping parts, the work he and I and my brother did, the
support from
the rest of our families & friends, well, it just wouldn't be the same on
another boat.

Not to say I wouldn't buy another boat TOO

I guess I'm generally of the mind of keeping the batteries somewhat on the
cheap side.
Not that I want them to fail, but it seems batteries in boats go every
couple years
anyway. Probably because while I try to store them properly over the winter,
I
can't get down there to "top them off" and and I don't like the idea of a
trickle
charger being connected for weeks at a time without me stopping by to make
sure everything is OK.

Again, Thanks for the comments!
Gary

Thanks for the good comments. I will consider if Group 27 will fit. I'm a
little
confused by the deep-cycle vs. dual use. If deep-cycle will be OK for
starting
then why ever buy/make a dual-use?

You might compare the CCA and the scale weight of a dual purpose battery with
both a starting battery and a deep cycle. I haven't done so, but the comparison
might be interesting.

Starting batteries use thinner plates to create a greater area of exposure to
electrolytes. This results in a greater number of CCA in a given battery size.
Downside, those thin plates disintegrate faster during severe
discharge/recharge cycles..

Deep cycle batteries use heavier plates, at the expense of some CCA. The
heavier plates will withstand serious recharging with less damage than the
lighter plates in starting batteries.

Dual purpose could be anything. A starting battery with such a short warranty
or high margin that the mfg figures he can afford to replace a few under
warranty. A "medium duty" battery slightly heavier than a starting battery but
not as rugged as a deep cycle. A genuine deep cycle battery labeled "dual
purpose" to rake in a few sales from folks who think they have to have a
different battery technology for starting the engine than for running DC loads.
Who knows?