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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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