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Hi
Randy,
All topics
are open to comment. Feel free to "butt in" whenever you
like.
Jon
Hi fellows,
I just got home after a 2 week trip and found over 100
psub emails; this is great; Im starting to think i may actually learn
something about psubs. This is my first reply (this is open comment I
hope if not please tell me to butt out and I will ). I have had two battery
explosions and both were from internal battery failure, venting was not a
factor. the first one was about 30 seconds after i hooked jumper cables to a
weak battery. Brent you are wise with your precautions because by the time i
got to wash up my hair was coming out by the hand fulls. The second one was
simply starting my pickup and it blew with such force that it distorted some
nearby sheetmetal( what would have happened if it was a 6 or 8 battery bank).
I too have been leaning toward isolated external battery pods. my thoughts are
to seal the endcaps with o rings
and hold the caps in place with 4 small bolts in tension
pulling the caps enough to compress the o ring to seal the pod when near the
surface. In this way, should there be an explosion in the pod you will have
just launched your first torpedos, one in each direction. As long as the bolts
are not to large the pod and sub should be ok. Im interested in your thoughts
on this approach
thanks
Randy
----- Original Message -----
Sent: Tuesday, August 07, 2007 11:07
PM
Subject: RE: [PSUBS-MAILIST] Real Live
Submerge Testing on a 12 VoltLawnmower Battery
James,
I've always planned on installing sealed batteries in
my subs. I can see that having any kind of spark producing item in the
pod(s), like the fuse mentioned in Vance's story, would be bad news. I like
the idea of having the batteries in one or more pods. If there is a water
leak in the pods containing sealed type batteries, that can't be pumped out
with a high pressure sump pump that is just outside the pods, is there a way
to fill the pod with a fire suppressive foam, you can activate or that can
activate automatically? Or have valves on the top and bottom of the pod(s)
that can be remotely opened to free flood the pod in trouble with water, so
that the gases produced from being under water would just leave the pod(s)
and not build up in the pods. Also if you coat the post and any
other exposited parts that will react to water touching them in mass,
with a rubber insulating coating like you can
dip tool handles in, I would think that might help allot. It would
make maintenance harder but that's the trade off for making the sub
safer. Can all the connections be potted in
epoxy?
I like
the idea of not venting the pods into the sub. The K-350 design vents the
battery pods into the main hull when charging. I never liked that
much. I know they cap them off when in use but still not what I want.
What
about making the pods double hulled with two hatches, to double your chances
of stopping a water leak, even in a
collision.
Regards,
Brent
Hartwig
From: lil_brother_llc@bellsouth.net
To:
personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Real Live
Submerge Testing on a 12 VoltLawnmower Battery
Date: Tue, 7 Aug 2007
23:39:30 -0500
Brent,
I appreciate the fact that you ambitious enough to
do battery testing. I don't know if I would have went that far.....but
since you did, here are some things I have considered.
Not all batteries are sealed......I would probably
try and design my sub to have a very good (read low) power demand. I would
try and save every amp I could in places that it would be relatively
priced.
I would also try and use sealed batteries. They make
sealed batteries in various sizes, and types.
I would also explore the possibilities of locating
the batteries in a pod not connected to the crew compartment (not vented
to it). This can still cause an explosion....which at depth would be like
a depth charge, but the chances of sparks have been reduced. Also a leak
detector could be placed inside the separated pod to inform of water
intrusion.
All of these ideas have problems....but they prevent
a large number of problems in an emergency.
James Long
Owner/Designer
Lil Brother LLC (Instrument
Division)
----- Original Message -----
Sent: Tuesday, August 07, 2007
11:05 PM
Subject: RE: [PSUBS-MAILIST] Real
Live Submerge Testing on a 12 VoltLawnmower Battery
Good Evening
Vance,
Thank you for taking the time to post the below
information. True I don't plan to use lawnmower batteries in my subs. I
used that battery for a number of reasons; it's a 12 volt DC none sealed
lead acid battery, basically like most batteries used in private subs in
the past and present, it would be cheap to replace if damaged in the
test, smaller battery = smaller explosion and/or shock, and it's what I
had in hand.. I would expect a larger non sealed lead acid battery to
respond in the same basic way. I did the test to learn how to be safe in
a submarine, and so I could design as safe of a sub as I could. For
safety, I filled the bucket remotely from over 50 feet away, and behind
a corner of the house, and the bucket was 30 feet from the house on
concrete. When I did the jumper cable test, the battery was 6 feet away
from me on the other side of the bucket, and I was wearing allot of
protective clothing and a full face shield in case the battery exploded
and through battery acid at me. When ever I work on a battery, or use
jumper cables, I use protective eye wear at a bare minimum. I don't know
how many times I've done and seen car engine compartments, including the
battery, pressure washed with no apparent ill affects on the battery, or
the person doing the washing nor the dogy in the
window.
Having a battery explode in a enclosed hardened container,
is not the same as it exploding in an open area. If I put a cup of
gun powder on the concrete and light it remotely, you'll get a big flash
and not much else. Now if you put that same amount of powder in a hard
container, like a pipe with threaded end caps, you now have a whole
nother animal. Hydrogen and/or chlorine gas exploding in a sealed
contain because they got lit from a fuse is not the same as having a
battery in the compartment with you, and it getting covered with water,
unless you light the gas(s) some how after they build-up. In that story
the gas exploded from a fuse igniting it, not just the batteries
exploding on there own.
Time
will tell if my mower battery is toasted, but I don't think it would be
damaged, since myself and many others use larger and smaller batteries
of all kinds to produce colloidal silver and hydrogen by
way of electrolysis by using electrodes. Much like I did
with the jumper cables. These batteries get drained over time, but
nothing else. We just charge them again and again. I would highly
suspect that having the battery submerged does the same basic thing, and
just slowly drains the battery by producing hydrogen
and oxygen tell spent. It's very true that a higher voltage
and amperage system would produce allot more hydrogen and oxygen faster,
of which I wouldn't want to be around, but that in and of it's self is
not an explosion of the battery(s) until it gets ignited some how by
something else besides the battery. I would think it would take some
time to fully discharge the batteries in that manor. Now having
batteries directly connected with wires that can act as an heating
element would be very uncomfortable, if the fuses and/or ground fault
protector(s) didn't work correctly.
Now
I didn't touch the jumper cable ends together underwater while the
battery was submerged, and I didn't open and expose the battery acid to
the water. So that is another matter. That would be testing the battery
submerged while under load, if I touched the cable ends together above
or below the water or hooked them up to a car light or a electric motor.
Having the battery by it's self submerged and producing hydrogen
and O2 off the negative post, I would think could be
considered testing while under a light load, depending on the salt
and/or mineral content of the
water.
Regards,
Brent
Hartwig
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST]
Real Live Submerge Testing on a 12 Volt Lawnmower Battery
Date:
Tue, 7 Aug 2007 16:29:12 -0400
From: vbra676539@aol.com
Brent,
Will you be using lawnmower batteries for your submarine? I'm
thinking not, and I'm also thinking that you need to talk with the
manufacturers. Your experiment had somewhere in the neighborhood of
exactly zip to do with a seawater intrusion incident, which has more
to do with voltage levels and maximum load potential than anything
else. Offshore, we often used a plastic barrel of seawater to deep
discharge banks when equalization was necessary; just take two cables,
positive and negative, add a couple of feet of copper to the ends, and
dip. You'll get boiling water in no time, my friend, trust
me.
As for chlorine gas, let me give you a cautionary
tale--two, actually, one of which I was involved with. Two battery
explosions, one on PC-9 and one on the old PLC-4. The former made
VISIBLE chlorine gas (it really is green, by the way), and the latter
blew a two hundred pound hatch completely off the submarine, all the
way across the shop, and THROUGH a tin wall. Those were both 120 volt
systems, with a 220 amp capacity. PC-9 got flooded with seawater due
to a pod leak, which caused the violent discharge, which caused the
acid to boil, which separated water into hydrogen and oxygen,
which ignited and caused a horrific bang, pretty much in that order.
Deep Diver had its charging vent closed during charging (an
oversight), bubbled out gas, and when the overload came (from the
over-charging), popped an internal in-line fuse, which made a spark,
which made another one of those horrific bangs, and might well have
killed a few people, had they not all been outside for lunch,!
possibly congratulating each other on how clever they
were.
Testing is one thing, my friend, but Ben Franklin at
least had enough sense not to fly a kite on metal wire. Otherwise, we
might never have heard about it. I'd hate for the same thing to happen
to you. And, if I had to guess, I'd say your lawnmower battery
probably has some warped plates, which means it ain't going to last
much longer, all things considered. No harm, no foul? Maybe, but
PLEASE, don't let this get to be a habit. There's as awful lot of
potential in a battery bank, and it'll bite your butt if you aren't
careful.
Best Regards,
Vance
-----Original
Message-----
From: Brent Hartwig
<brenthartwig@hotmail.com>
To:
personal_submersibles@psubs.org
Sent: Tue, 7 Aug 2007 2:54
pm
Subject: RE: [PSUBS-MAILIST] Real Live Submerge Testing on a 12
Volt Lawnmower Battery
Ron, When the battery was in seawater, the water slowly
turned yellow. I'm not sure why. I don't have a way to test for
Chlorine gas at the moment. Is there a cheap test, can you smell it?
I'm not sure I want to smell it. When I make colloidal
silver by electrolysis of pure silver electrodes, the distilled
water becomes a light yellow. Perhaps the lead post are sluffing off
lead into the water.
Regards,
Brent
Hartwig
Date: Tue, 7 Aug 2007 10:23:07 -0700
From: ronleonard@shaw.ca
Subject:
RE: [PSUBS-MAILIST] Real Live Submerge Testing on a 12 Volt
Lawnmower Battery
To: personal_submersibles@psubs.org
Anyone
heard that a battery submerged in salt water produces Chlorine gas?
From those in the battery industry that I have asked it would
appear to be true.
If
it is correct, that would be a much larger problem than getting
shocked or splashed with acid.
Ron
Well
Boys and Girls, I did some testing.
Ya I know
that usually means vacate the area with or without your shorts, to
another county. But it's to late, I already did it. One can talk
about it for only so long before they get off there arss and get
dirty. It's more fun to.
So I
removed a fully charged 12 volt lawn mower battery, I could do with
out until next week, if it blow up anyways, and I did some
testing. I then obtained a five gallon bucket, jumper cables,
lots of protective clothing, and a full face shield, among other
things. I then put the battery in an empty bucket and then put the
end of the hose into it. Then I remotely filled the bucket with
slightly hard freshwater, I don't remember what the PH of my water
is. Nothing happened, or at least that's what I thought at
first. I then removed the water and battery from the bucket
and attached jumper cables to it in the normal fashion. When
striking the ends of the cables together I got the normal sparks.
When I put them underwater there was some weak hydrogen production
from the negative lead. Then when I touched the leads together
underwater, I got the same basic spark as I did out of the
water.
Then I went
and found my old stash of aquarium stuff, and pulled out some
Instant Ocean brand sea salt and mixed it in freshwater, until I got
a specific gravity of 1.21, like most sea water. I then removed the
freshwater from the bucket and added the saltwater for some more
testing. I tested the leads in the same way and got the same
result, but with a bit more hydrogen production from the negative
lead.
Next I
added enough salt into the one gallon in the bucket to make three
gallons of sea water, so I could completely submerge the battery.
But before I added the water I mixed in the salt and tested the
leads again.. Now when I put the leads into the water on either side
of the inside of the bucket, the negative lead produced allot more
hydrogen. When I then touched the two leads under water there was a
larger spark on the tangent surfaces and they tried to stick
together. They didn't try to stick together in freshwater and not
much in normal sea water. Point is that if you take your sub
to the Great Salt Lake in Utah be
careful.
Now I added
two more gallons of freshwater to the mix, to get a specific gravity
of 1.21 again, and put in the battery remotely. Nothing much
happened, just some hydrogen production from the negative pole. This
was just a cheap normal battery, not a AGM sealed type. I then did
some testing and then put my bare finger in the water. Nothing, not
even a tingle. I then lowered the level of the water to about an
inch over the top of the poles. Then did some more testing and then
put my finger directly between the poles, nothing.
I then
removed the salt water and refilled it with freshwater and did the
same testing, nothing. I would say that the battery would of slowly
discharged by producing hydrogen until spent.. No explosion
when submerged in this way. The hydrogen in an enclosed space would
be real bad news. You'll be safer in freshwater then salt since
you'll have more time to get out before the hydrogen levels get to
high. Still you better get out ASAP unless you can route the
hydrogen into your AIP unit quickly. ;
)'
Finally I
reinstalled the battery in the mower and started the mower with no
trouble. I learned allot from doing this, how about you? Just
remember I'm a submarine half full kind of
guy.
Here are my
pictures of the submerged battery
testing.
http://www.frappr.com/?a=viewphoto&id=4001713&pid=7357670
Regards,
Brent
Hartwig
"Do
or do not, There is no
try"
~ Yoda =
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