Larry,

Satisfy my curiosity here. I've seen the aftermath of two battery
explosions so I know they happen and are serious when they do.
However, with all those cars racing around bouncing and jolting their
cheap, thin plate batteries that usually aren't replaced until the
motor won't turn over, I've never heard of an auto battery explosion.
I'm sure they happen but it's got to be statistically rare for one not
to have come to my direct notice.

I understand that the AGM cells in my boat are a wrapped sandwich of
glass mat and the lead plates. How can contact between these plates
be very likely? Is the boat just sitting there motionless more
likely to have these well supported plates bend than all those cars
sitting in unheated garages and out on the street? First, the
batteries have to discharge which seems pretty unlikely with the
cables disconnected. My wife has to have AAA jump start her car a
half dozen times a winter because she doesn't close the doors all the
way or leaves the lights on. No problem so far.

This seems like a several orders of magnitude lower risk than the boat
falling off the jackstands.

--

Roger Long

On Sun, 29 Oct 2006 13:27:48 GMT, "Roger Long"
wrote:

Satisfy my curiosity here. I've seen the aftermath of two battery
explosions so I know they happen and are serious when they do.

It's my understanding, perhaps incorrect, that most battery explosions
occur while charging. Charging releases hydrogen which can and will
explode under the right conditions - poor ventilation, spark, etc.

The risk of an idle battery exploding is just about nil, otherwise it
would be happening all the time.

Roger Long wrote:
Larry,

Satisfy my curiosity here. I've seen the aftermath of two battery
explosions so I know they happen and are serious when they do.
However, with all those cars racing around bouncing and jolting their
cheap, thin plate batteries that usually aren't replaced until the
motor won't turn over, I've never heard of an auto battery explosion.
I'm sure they happen but it's got to be statistically rare for one not
to have come to my direct notice.

I understand that the AGM cells in my boat are a wrapped sandwich of
glass mat and the lead plates. How can contact between these plates
be very likely? Is the boat just sitting there motionless more
likely to have these well supported plates bend than all those cars
sitting in unheated garages and out on the street? First, the
batteries have to discharge which seems pretty unlikely with the
cables disconnected. My wife has to have AAA jump start her car a
half dozen times a winter because she doesn't close the doors all the
way or leaves the lights on. No problem so far.

This seems like a several orders of magnitude lower risk than the boat
falling off the jackstands.


Roger,

Larry may have a different view, but my
understanding is that battery explosions
are almost always caused by the release
of explosive gas (usually caused by
overcharging). Battery installations in
boats typically involve small, closed
compartments. Contrast that with
automotive installations in which there
is usually a good flow of air through
the battery compartment and it becomes
clear why automotive battery explosions
are far less common than those in boats.

So perhaps the focus might be better
placed on adequate battery compartment
ventilation: a low-cost, low-tech
solution that could reduce the
probability of a battery explosion in a
boat to that of a similar battery in an
automobile.

I've seen no statistics on steam
explosions so I can't comment on that
except to agree that these would be as
likely in an automobile as they are in a
boat, and are virtually unheard of in
the former.

I do enthusiastically endorse Larry's
suggestion of a simple timer on an
unattended battery charger, BTW.

Chuck

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Electrolyte freezes at different temps depending on it's charge
due to the fact that it's specific gravity changes depending on that charge.

From the Trojan Battery web site, a fully charged battery is good to -92
degrees.
At 40% state of charge, it will freeze at 16 degrees.

I've left flooded Rolls Batteries through the winter with no problem.
I'm in Maryland, so you're looking at typical winter temps of 20 to 40
degrees night/day
with an occasional cold snap getting into the single digits for a couple of
days.
(At 280 lbs each, I refuse to wrestle them on and off every winter!)

I don't think you'll have a problem.

T.O.


"Roger Long" wrote in message
...
Larry (or whoever else jumps in),

I know there was a recent thread on this but Google didn't turn up the
clear answer I'm looking for.

I know it's theoretically better to keep batteries on a trickle charge and
warm over the winter but it costs me $70 to have them taken out of the
boat and stored by the yard. (Nevermind the reasons why I don't want to
take them out myself and home to my basement.)

I've got a good three stage charger in the boat. If I put a good charge
on my two AGM's just before the shrink wrap goes on and leave them till
early spring with no further attention, will I have reduced their life and
strength enough that the $70 would have been a good investment? If the
difference between warm, charged, and dead, cold storage is just around
the theoretical margins, I'm inclined to leave them in place this year.

I'm in Maine which isn't quite as cold as people think, at least on the
coast. These two year old batteries get pretty light use with a 15 hp
diesel, a few lights, and frequent dockside charging from shore power. I
don't leave the charger on all the time so they don't micro cycle but they
seldom get pulled down very far either.

--

Roger Long

"Roger Long" wrote in news%11h.492$xw1.375
@twister.nyroc.rr.com:

I understand that the AGM cells in my boat are a wrapped sandwich of
glass mat and the lead plates. How can contact between these plates
be very likely? Is the boat just sitting there motionless more
likely to have these well supported plates bend than all those cars
sitting in unheated garages and out on the street? First, the
batteries have to discharge which seems pretty unlikely with the
cables disconnected. My wife has to have AAA jump start her car a
half dozen times a winter because she doesn't close the doors all the
way or leaves the lights on. No problem so far.


Oh, the cars have their share of battery explosions, usually from the
unfused alternator diodes shorting to ground or the frozen starter with
the shorted commutator. However, it's not much of a mess in a car where
the acid bath is so easily washed away as soon as it happens, and is,
mostly, forgotten, unless it exploded when the WIFE turned the key,
which, of course, is all YOUR fault. The batteries, usually, don't short
internally plate-to-plate because of the separator....as long as they
don't get hot when the supercharger screws up and puts 40A to them for a
couple of weeks while you're ashore or the boat alternator diodes that
ALWAYS have DC voltage on them with the key off, short same as the car.

I had a red AGM battery that came with my government-surplus Chevy diesel
stepvan "go off", by the way. That was an internal short. It didn't
explode, I suppose because the short wasn't a dead short. It simply
MELTED as the plates became so hot it blew the safety pressure valves out
of it and boiled the electrolyte in the gauze into steaming sulfuric
acid. The cell that shorted, took out all the other cells because it
melted from its cylinder into their cylinders. I swapped it with an AGM
dealer who gave me a nice credit against another AGM battery priced like
a Lexus front end. Luckily, the one that melted opened from post to post
so it didn't also short the other one in parallel with it used to crank
the 6.2L diesel V-8...which now runs on free frying oil from 3 chinese
restaurants...(c; (www.frybrid.com)

Larry
--
I sure hope Halloween comes real soon....
I've run out of Halloween candy THREE TIMES SO FAR!

Larry wrote:
"Roger Long" wrote in news%11h.492$xw1.375
@twister.nyroc.rr.com:


I understand that the AGM cells in my boat are a wrapped sandwich of
glass mat and the lead plates. How can contact between these plates
be very likely? Is the boat just sitting there motionless more
likely to have these well supported plates bend than all those cars
sitting in unheated garages and out on the street? First, the
batteries have to discharge which seems pretty unlikely with the
cables disconnected. My wife has to have AAA jump start her car a
half dozen times a winter because she doesn't close the doors all the
way or leaves the lights on. No problem so far.



Oh, the cars have their share of battery explosions, usually from the
unfused alternator diodes shorting to ground or the frozen starter with
the shorted commutator. However, it's not much of a mess in a car where
the acid bath is so easily washed away as soon as it happens, and is,
mostly, forgotten, unless it exploded when the WIFE turned the key,
which, of course, is all YOUR fault. The batteries, usually, don't short
internally plate-to-plate because of the separator....as long as they
don't get hot when the supercharger screws up and puts 40A to them for a
couple of weeks while you're ashore or the boat alternator diodes that
ALWAYS have DC voltage on them with the key off, short same as the car.

I had a red AGM battery that came with my government-surplus Chevy diesel
stepvan "go off", by the way. That was an internal short. It didn't
explode, I suppose because the short wasn't a dead short. It simply
MELTED as the plates became so hot it blew the safety pressure valves out
of it and boiled the electrolyte in the gauze into steaming sulfuric
acid. The cell that shorted, took out all the other cells because it
melted from its cylinder into their cylinders. I swapped it with an AGM
dealer who gave me a nice credit against another AGM battery priced like
a Lexus front end. Luckily, the one that melted opened from post to post
so it didn't also short the other one in parallel with it used to crank
the 6.2L diesel V-8...which now runs on free frying oil from 3 chinese
restaurants...(c; (www.frybrid.com)

Larry
You ARE paying the state and federal road tax aren't you?

On 28 Oct 2006 12:58:54 -0700, "
wrote:

The best source that I found for solar panels is Wholesale Solar.

http://www.wholesalesolar.com/

The prices were so cheap that I was almost afraid to use them. I did
and have been very please with them.

-Lee

gosh, so cheap they're only $150 more than they were 4 years ago.
assholes.


Eisboch wrote:
"Jeff" wrote in message
. ..

Eisboch wrote:


150 watt solar panels? Who makes them? And they work installed under
the shrinkwrap?

They are three 50 watt panels, on the hardtop. On a sunny day, they do
get into "charge" mode. I've never read the exact current, but perhaps
this winter I'll have a chance because I have a new charge controller that
reads the current.

Also in the late winter, I cut a hole in the shrink over one of the
panels, and from that point on there is plenty of juice


Cool. I had a single, 50 watt panel on an RV. Direct sunshine produced
slightly over 2.5 amps.

I thought you had a single, 150 watt panel and was curious where you got it.

Eisboch

krj wrote in news:VUe1h.77602$zF5.2131
@bignews1.bellsouth.net:

You ARE paying the state and federal road tax aren't you?


Oh, sure.....Yeah.....right....

If they come and ask for it, nicely, without the guns.

Larry
--
I sure hope Halloween comes real soon....
I've run out of Halloween candy THREE TIMES SO FAR!