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Hi Brian.
Thank you very much for that info on Dan Lance's
epoxy wire connectors Brian.
Do you have the link or know where I can read or
see more info on it? That sure would be great. I see what you mean. If I sealed
the ends of my wires going into the battery pod with epoxy except for the round
connector that attaches, and if somehow my epoxy got a crack in it from stress,
hydrogen could then ingress into the wire and go into the motor housing. Having
that system you spoke of would preclude that and add an extra safety margin.
Love to read more on this.
I must admit I know very little about gel or AGM
batteries, so I can't help you there. My knowledge is limited to lead
acid.
If you do use lead acid batteries you will not want
to submerge the batteries completely in oil otherwise you will contaminate your
cells with oil. Hence, you have to leave an air space at the top of the
batteries and the outside water pressure will still
act against that small amount of air and try to
ingress and or push in on the lighter material you spoke of using and possibly
implode your pod. Plus you might not want to just leave a few inches of air over
your lead acid batteries above the oil because then you might get splash
from the oil that would wave over the top of your batteries and possibly
contaminate them.
You might be able to use the oil method and
completely submerge your batteries with other types of batteries that were not lead acid, but of these types of batteries as
I said, I have no knowledge.
Some time ago I had an idea that if you used a
battery that was non lead acid and totally sealed, why not just encase that
battery and its wires completely in epoxy, and
then it would not even need a pod.
Just strap the epoxy encased battery under the
sub and then just run the wires coming out of the epoxy to the motor shaft and
seal the junction where the wires went into the shaft. Sounds plausable to me
but I don't know that much about batteries except
for lead acid. Except I DO know all the other types are a lot more expensive
than lead acid. In my epoxy encased battery idea I guess you would build in
some kind of provision for wires coming out of
the epoxy to go to your charger and waterproof
them. If someone could come up with a battery pack like this it sure would
make things easier for us wouldn't it? An epoxy encased battery pack that
contained no air. You could even use clear epoxy and actually see thru it to the
batteries slung under your sub. No outside water pressure equalization would be
necessary because their would be no air around the batteries with them being
encased in epoxy. It would be heavy but this would be ok and act as a keel to
keep you upright
and you could compensate with air bladders in the
wetsub body.
But I have never heard of anyone manufacturing
anything like this. Maybe someone out there will read this and manufacture
them. Lol. We should be so lucky.
Most of the posts I have read from various sites
showed people using transformer oil in their motors for those who used the oil
method of equalization. Some believe it or not use water with corrosion
inhibitors in it to equalize the motor housing.
But I have read nothing concerning using oil in the
battery pods.
I personally think (with what I know at this time),
that air equalization of the battery pod when using lead acid batteries is the
way to go. I am by no means an expert, but it seems so simple to just use a pvc
battery pod and air equalize it.
Well.....simple is subjective, lol, that's why I
haven't completed mine yet. But I don't think I would completely submerge lead
acid batteries in any kind of oil if I were you. And therein you still have an
air space over them to deal with and equalize.
As I have recognized and others have mentioned, pvc
is very strong and for normal scuba depths probably doesn't absolutely need
equalization anyway. But I am going to equalize mine. I think it is better to
not have the water pressure trying to get in past a small
juncture and pressure equalizing would
basically keep any pressure off my battery pod which I think is
good.
If I find that my battery pod needs more ballast to
be either neutrally buoyant or just a little negative buoyant, (I want it a bit
weighted to act as a keel to preclude upending) then I will use scuba
weights which will be lead pellet bags which will conform around the areas of
the batteries in the pod. I could use sand but
that would be kind of messy every time I wanted to pull the batteries out to
inspect them.
Kindest Regards,
Bill Akins.
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