On Jun 16, 12:58 am, Salomon Fringe wrote:
Well the author of the Victron article really did a good job and I have
used his info extensively but I did realize that Victron sells gel and
AGM but nothing else in terms of batteries so I assumed a slight nudge
towards their product line in the numbers. ...

Now wait. You're accusing the guy of lying to sell overpriced
batteries that will fail if they ever get used and you're saying
you've used his "info" extensively? Is this wise?

Also his pricing info in the
comparison was way off from what I found, e.g. full traction was just
50% of the price he stated.

Pricing changes all the time. Still, I think he was testing 24v full
traction batteries which might well explain the difference.

... in real life, a flooded cell will hugely outperform the AGM
for cycling use because you can equalize a flooded cell to refresh weak
cells, because you cannot monitor the temperature of each battery (let
alone every cell) while charging which means guaranteed overcharging of
some batteries/cells - destroying your typical AGM cell. Of course it is
cheaper, too.

Just for the record, you can equalize AGMs periodically without
destroying them. The manufacturers even recommend it. I use a
temperature compensated charging system with my AGMs. I don't
understand what you're saying about not being able to monitor the
temp. Your theory about cycling is interesting and testable but it
goes against the published data. Given that I think the burden of
proof lies with you. Go do some tests that suggest that the
datasheets and experts are wrong and you'll garner a lot of
attention.

....
I would like to know from people who have REALLY deepcycled their AGM's
500 times (anybody counting?) and are still using them. If these exist I
believe that you will find they paid as much for their AGMS as they
would have for equivalent capacity traction - which would last at least
twice as long.

I presume what you're saying here is that my experience of REALLY
sailing three times around the Pacific and REALLY living on my boat
full time and REALLY charging my batteries using my engines is REALLY
not valid because you REALLY don't want to hear it? I'm not claiming
to be a representative sample but my experience suggests to me that
some of your concerns about AGMs are overstated. I cruise extensively
and keep in touch with many who do the same and I haven't heard any
negative feedback about AGMs. Again, that's not a random sampling,
but still, here we are in a widely read newsgroup discussing AGMs.
Where are the voices saying "damn, I put one of those in and smoked it
in a week"? Where are the 500 e-mailers who wrote into the Dutch
magazine to complain about AGMs?

I think Roger is right. The discussion has wandered off a bit. I'm
not trying to get into a ****ing match. I don't sell batteries. When
I bought my AGMs it wasn't a slam-dunk, easy decision. I can
understand why lots of folks choose differently. I've been very happy
with the way my AGMs have worked, but performance was not the only
criteria in my decision. As I type this at my nav station, I have two
8D AGMs just a foot or so away from my toes. Safety and aesthetics
have some value for me, too. AGMs are much more shock resistant than
flooded or gel batteries and that makes them less prone to internal
plate failures and shorts. Reliability is important, too. And so it
goes. In different circumstances I can easily see myself doing things
differently. There's lots of room for discussion of the pros and cons
of various systems. My only serious beef with the discussion so far
is with some of the arguments and assertions in your first link which
are, to be kind, bogus.

--Tom.