Charlie Morgan wrote:

. They also charge faster than flooded cells due to lower internal
resistance.

I hadn't heard that but can believe it.

The significant differences I'm aware of are the lack of convection cooling
when you try to charge them more quickly than a reasonable boater would want
to and the inability to tweak and replace the electrolyte after they have
been abused. Neither should be an issue with normal use.

I'm sure we'll hear from Larry shortly but I can't see any good reason to be
carrying semi closed containers of liquid acid around inside my sailboat.

--
Roger Long

"Roger Long" wrote in message
...
Charlie Morgan wrote:

. They also charge faster than flooded cells due to lower internal
resistance.

I hadn't heard that but can believe it.

The significant differences I'm aware of are the lack of convection
cooling when you try to charge them more quickly than a reasonable boater
would want to and the inability to tweak and replace the electrolyte after
they have been abused. Neither should be an issue with normal use.

I'm sure we'll hear from Larry shortly but I can't see any good reason to
be carrying semi closed containers of liquid acid around inside my
sailboat.

--
Roger Long

Everything I've read on battery maintenance says to NEVER add acid to the
cells -- only distilled water. Now granted, someone, somewhere, at some time
had to have put acid in those cells, and proper fluid level may give an
improper mix... maybe? Still, I think I'll stick with adding water only.

"KLC Lewis" wrote

Everything I've read on battery maintenance says to NEVER add acid to the
cells -- only distilled water.

Quite right. The semi closed containers I was referring to are the
batteries themselves. Checking the electrolyte and adding distilled water
is still an operation that involves (or should) goggles and acid in the
often confined and contorted spaces of a sailboat.

* Gogarty wrote, On 6/2/2007 7:48 AM:
In article xGW7i.8$Uy4.3@trndny09, says...

I need to purchase two new batteries. Part # DC 24

That is Deep Cycle .. and 24 refers to size.

I know, West Marine sells batteries. I just figured maybe someplace else
has a better product.

How about Sears? Or XXXX?

Any recommendations?

Size 24 seems small. Our boat originally had 27s. We upgraded to two 4D for
house batteries and a 27 for a starting battery. At the time, we bought
Rolls. They lasted about one day longer than the warranties, i.e., four
years. The case on one of the 4Ds even broke. Damn good thing it was in a
battery box. I reported it to Rolls but they didn't seem very curious about
it.

Wow! If you could crack the case of a Rolls after 4 years, you really
did something nasty to them! The only way that I know is to leave
them flat over a cold winter (that's what I've done), though I suppose
severe overcharging could also do it. And of course, if one was
dropped, it could have a hidden flaw that would show up later.


We now have Exides all around and I'll bet they will last just as long as
the Rolls at one third the price.

My advice: buy deep cycle wet cell maintenance free at as good a price as
you can find.


The question you have to ask though, is if you could crack a case on a
Rolls, what are the chances that a "maintenance free" (that is,
impossible to maintain) battery surviving the same abuse? This is why
I chose Trojans, which I was able to get for 20% over the Exides.
They should withstand "normal abuse" and while not the same as Rolls
or Surrette, they are stronger than normal batteries.

In any case, I don't think I would get a "maintenance free" unless I
was just daysailing and weekending - the odds of an abrupt failure
seems rather high. If the regulator wire fell off a fair amount of
water could be boiled off in short order. In a normal battery you can
simply add the water back. In a "maintenance free" this is a
permanent loss, perhaps a killer. My maintenance free starter
batteries lasted about 3 years - I replaced them with AGM's.

I had a friend who was the epitome of the "absent minded professor" -
he would leave his door wide open when he went on vacation, and if
there was anything he could leave running, he would - he always bought
the cheapest battery because he knew that whatever he got, it wouldn't
last the season. At the end of the season, he would be starting the
engine in the slip, and then leaving it running all day, because it
was doubtful it would start off the battery. For him, the cheapest
probably is the best.

You had one set of batteries all explode and the next set of heavy
duty batteries (which should go 8-10 years) all die in 4 years (one
with a cracked case), and you don't think there might just be
something wrong with what you're doing?

I'm sure the Rolls guy wasn't interested at all because everyone
always claims they never abused the batteries ...




* Gogarty wrote, On 6/2/2007 11:14 AM:
....
The batteries were not abused. They were always fully charged going into
winter storage and started the engine instantly when first tried in the
Spring. They were also regularly watered. I have no idea why that one battery,
in a great big Blue Sea battery box, where it was not subject to shock loading
of any kind, cracked open. I have photos but can't post them to this group.
What really got me was that Rolls was so incurious. But like the one horse
shay, all three batteries died within weeks of one another. Most peculiar.
....
What abuse? On shore power we have a True Charge smart charger that seems to
work very well and at sea a high output alternator with suitable smart
regulator. I take my batteries seriously. A pair of 4Ds is after all a pretty
hefty bank.

....

I have had some very bad experience with batteries. The original batteries in
this boat were no-name 27s hooked to a really cheap ferro resonant stupid
charger. Early on I upgarred both the charger and the engine charging system
but not the batteries. The batteries went gradually bad. One day at the
beginning of the season (March 30) I was moving the boat from one slip to
another at idle speed and then decided to rev up to cruising speed. Bang!
Bang! Bang! All three batteries exploded. Steam explosions, not hydrogen
explosions. You want acid all through your boat?

* Gogarty wrote, On 6/2/2007 5:30 PM:
In article ,
says...

You had one set of batteries all explode and the next set of heavy
duty batteries (which should go 8-10 years) all die in 4 years (one
with a cracked case), and you don't think there might just be
something wrong with what you're doing?

The exploding set were indeed abused. But not by me.

Oh come on! Three batteries do not explode simultaneously from abuse
that happened years before. They explode from charging at 18 Volts
because the regulator had a problem.




I'm sure the Rolls guy wasn't interested at all because everyone
always claims they never abused the batteries

No doubt. To the point that the case cracks open, however?..

I've done that to an old Surrette by letting it go flat and freeze
during the winter, but its hard to see it happening in normal usage to
young Rolls. BTW, the warranty on Rolls marine batteries is 7 or 10
years, depending on the model. If yours were only 4 years old, you
had new ones coming to you.

I'm thinking you have a latent problem in your system. I had two in
mine: One was that the starter battery was hard wired to the engine,
but the regulator was sensing the house bank. This wasn't a big
problem when the combiner latched the batteries together, but if it
didn't for some reason, it was possible to overcharge the starter bat.
This was solved by breaking the connection between the alternator
and the starter and running a dedicated cable. The other problem was
a connection on the regulator control wire that could on occasion
catch some rain water if a hatch drain clogged.

Both of these problems resulted in severe overcharging - the only good
thing is the the battery getting zapped was right behind the helm and
the smell was unmistakable so it could be dealt with promptly.
However, if I had let it continue I'm sure the battery would have blown.