Wayne.B wrote:
On Wed, 01 Feb 2006 18:12:14 -0500, Jeff wrote:


I was in my marina office asking if they could match they price I had
for 4 Trojan 105 6 Volts ($280 from a golf cart company).


Sam's Club, usually about $55 each here in FL where there are a lot of
golf carts. It's about the cheapest way to get to 440 amp-hours that
I know of.

Was that for Trojans, or for generics?

On Wed, 01 Feb 2006 11:32:43 -0500, Jeff wrote:

Glenn Ashmore wrote:
I was talking to an engineer with a local school bus manufacturer yesterday
about Rutu's progress. I mentioned that I was leaning towards a high
capacity Group 31 battery to use for the starter bank. More than the 4JH4
needs but would give me a lot of reserve. He replied that was a bad idea
on a sailboat. Seems that they no longer equip their school busses with 925
CCA Group 31's because they have a very high self discharge rate. They are
great for regular highway use but school busses like sailboats spend a lot
of time with the engine off. The 620 to 700 CCA batteries hold their charge
much better and will last a lot longer in that type service.

Just another tidbit to store away for future use.

I've used AGM's for my starting batteries. The self discharge is very
low, and the cost isn't that high.

I've got a Harley Davidson AGM battery I use for the running lights on
my Zodiac. I charge it from the magneto in an old Honda four-stroke. I
didn't use it all summer (it last took a charge in July) and has lived
in a frozen garage. I was pleasantly surprised to read it gave 12.3
volts the other day. So I gave it an hour on a trickle charger and the
next day it read 12.6.

Good little battery and a nice introduction for me to the type.

R.

Someone help me out here. I always thought that the Group number just
specified the size/shape of the battery. Why would thhe size or capcity
affect its ability to hold a charge? Are you talking about a specific
manufacturer's battery? I can see how one manufactures group 31 my not, but
Group 31's in general?


"Glenn Ashmore" wrote in message
news:eC4Ef.15932$Dh.8853@dukeread04...
I was talking to an engineer with a local school bus manufacturer yesterday
about Rutu's progress. I mentioned that I was leaning towards a high
capacity Group 31 battery to use for the starter bank. More than the 4JH4
needs but would give me a lot of reserve. He replied that was a bad idea
on a sailboat. Seems that they no longer equip their school busses with
925 CCA Group 31's because they have a very high self discharge rate. They
are great for regular highway use but school busses like sailboats spend a
lot of time with the engine off. The 620 to 700 CCA batteries hold their
charge much better and will last a lot longer in that type service.

Just another tidbit to store away for future use.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

It is not all Group 31 batteries. Just the high capacity 925 CCA type.

Here is the service bulletin they got from their chassis supplier:
http://www.internationaldelivers.com...pdf/dyk128.pdf

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"johnhh" wrote in message
...
Someone help me out here. I always thought that the Group number just
specified the size/shape of the battery. Why would thhe size or capcity
affect its ability to hold a charge? Are you talking about a specific
manufacturer's battery? I can see how one manufactures group 31 my not,
but Group 31's in general?


"Glenn Ashmore" wrote in message
news:eC4Ef.15932$Dh.8853@dukeread04...
I was talking to an engineer with a local school bus manufacturer
yesterday about Rutu's progress. I mentioned that I was leaning towards a
high capacity Group 31 battery to use for the starter bank. More than the
4JH4 needs but would give me a lot of reserve. He replied that was a bad
idea on a sailboat. Seems that they no longer equip their school busses
with 925 CCA Group 31's because they have a very high self discharge rate.
They are great for regular highway use but school busses like sailboats
spend a lot of time with the engine off. The 620 to 700 CCA batteries
hold their charge much better and will last a lot longer in that type
service.

Just another tidbit to store away for future use.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Hello Glenn,

I am also skeptical. Couldn't find out what the CT-400 is or who wrote
it or why, but the idea that someone would make a high-capacity Group 31
battery and then recommend it only for frequent charging use sounds
almost counter-intuitive.

After a very quick check of Exide's battery application guide, it
appears that their only Group 31, 925 cca battery carries a 24-month
warranty! Talk about disposable.

They have other Group 31's with lower cca ratings carrying the same
warranty, and they also have Group 31's with lower cca ratings carrying
six and seven year warranties.

But it is probably a true statement that all of the Exide Group 31's
rated at 925 cca will not last long, for whatever reason.

A similar statement could not be made about ALL of the Exide Group 31's
with lower 925 cca ratings.

Make sense? Sounds like it might be coincidence.

Chuck

Glenn Ashmore wrote:
It is not all Group 31 batteries. Just the high capacity 925 CCA type.

Here is the service bulletin they got from their chassis supplier:
http://www.internationaldelivers.com...pdf/dyk128.pdf

I think what the bus company is saying about the batteries makes
perfect sense. You get CCA, the ability to put out a lot of power in a
short period, by having more plate surface area. The only way to get
more surface area in the same box size is to have more plates. More
plates will be thinner and less rugged. Reducing the space between
the plates also makes the changes in shape that is inevitable with
deep charging cycles more likely to cause plates to touch.

Self discharge should be primarily a function of surface area as that
is where the reactions take place. More surface area for more fast
output capacity has got to be a trade off for self discharge rate.
The only way to avoid these trade offs is to increase the size of the
box which is effectively what they are recommending when they suggest
increasing the number of batteries.

--

Roger Long



"chuck" wrote in message
link.net...
Hello Glenn,

I am also skeptical. Couldn't find out what the CT-400 is or who
wrote it or why, but the idea that someone would make a
high-capacity Group 31 battery and then recommend it only for
frequent charging use sounds almost counter-intuitive.

After a very quick check of Exide's battery application guide, it
appears that their only Group 31, 925 cca battery carries a 24-month
warranty! Talk about disposable.

They have other Group 31's with lower cca ratings carrying the same
warranty, and they also have Group 31's with lower cca ratings
carrying six and seven year warranties.

But it is probably a true statement that all of the Exide Group 31's
rated at 925 cca will not last long, for whatever reason.

A similar statement could not be made about ALL of the Exide Group
31's with lower 925 cca ratings.

Make sense? Sounds like it might be coincidence.

Chuck

Glenn Ashmore wrote:
It is not all Group 31 batteries. Just the high capacity 925 CCA
type.

Here is the service bulletin they got from their chassis supplier:
http://www.internationaldelivers.com...pdf/dyk128.pdf

"Roger Long" wrote in news:wRbEf.1929$5Q3.852
@twister.nyroc.rr.com:

deep charging cycles more likely to cause plates to touch.



I can tell this is gonna be a LONG thread....(c;

"johnhh" wrote in
:

Someone help me out here. I always thought that the Group number just
specified the size/shape of the battery. Why would thhe size or
capcity affect its ability to hold a charge? Are you talking about a
specific manufacturer's battery? I can see how one manufactures group
31 my not, but Group 31's in general?


They use special "Group 31 lead" that wasn't minted at the Franklin Mint
like Surette battery lead all is. They also use "ordinary acid", not that
special blend of highly purified, laboratory-grade, .99976% fine the $400
battery makers all use made in tiny batches by the same chemists that
invented Amsoil oils and insecticides. Obviously, the combination of
"Group 31 Lead" and ordinary acid in the cheap ordinary plastic case is
inferior to the $400 batteries only sold at fine marine chandleries like
Waste Marine, Boater's World and Doug's Marina and Tire....

Besides....Group 31 batteries all come in ugly black plastic, not those
pretty maroon or red cases that increase CCA and AH by over 40% when placed
in a fine yacht like a Bayliner or Sea Ray....

Larry wrote:
snip when placed in a fine yacht like a Bayliner or Sea Ray....

fine yachts indeed!
Recently I found out that there are actually 3 types of yachts cruising
the Great Lakes. Sitting in the cockpit of our sailboat soaking up some
sun and suds the following enlightening exhange was overheard on ch. 68
in the Killarney Channel.

"Sportsman's, Sportsman's, Sportsman's, this is the Lotsa Lettuce, Lotsa
Lettuce, Lotsa Lettuce over..."

"Lotsa Lettuce...this is Sportsman's good day sir"

"Ah yeah we've got a reservation and blah blah blah"

"Roger that sir, please say your length and type."

and in the stentorial tones summoned only by the likes of proprietors of
only the finest of fine yachts and perhaps Ted Baxter we heard in response

"Roger that, ahem, we're a 53 foot -insert dramatic pause here- Searay"

Well you can imagine what a revelation this was for us. As I was in the
middle of a rather largish gulp of the golden brew, my sinuses were
treated to an involuntary high-pressure beer rinse as the import of this
pronouncement washed over me. 3 types??!? Sail, power....and Searay?
My God! who knew???

prodigal1 wrote in :

"Roger that, ahem, we're a 53 foot -insert dramatic pause here- Searay"



Hmm...maybe he was trying to warn the dockhands that he was driving a big
boat made of putty so they'd be very careful not to bump it into the dock,
which may destroy it, unlike real fiberglass boats.

http://yachtsurvey.com/Fiberglass_Boats.htm

I can understand his wanting to warn them he was driving a Sea Bayliner....
(c;