Cousteau's subs used oil-filled batteries. Each battery was encased
in a battery box with a shallow inverted funnel acrylic lid. The
gasses rose from the cells to the neck of the inverted funnel, where there was a
valve to vent. I'm sure topping off the battery acid was a major
chore.
Since oil floats on water, you can eliminate air spaces without
contaminating the battery acid, and since oil is non-compressible, pressure
compensation is not required. As far as I know, oil filled lead acid
batteries are pretty much the standard for deep diving subs.
Stan
In a message dated 1/30/2005 12:26:48 P.M. Eastern Standard Time,
ojaivalleybeefarm@dslextreme.com writes:
That sounds very thorough, but on the epoxying
the end of the wires you might want to look at Dan Lance's Submersible
Penetrators presentation at the 2004 convention. It takes what you are
doing a little bit further and adds a layer of safety precaution. There
is a connection incased in the epoxy that in case of it getting pulled out the
wires simply separate leaving an epoxy seal at the
transition.
By using gel batteries can the hydrogen
gas problem be mitigated? I was planning on using gel batteries or
AGM.
I have been considering filling my whole battery
compartment with oil. As long as I make that space as minimal as
possible the actual amount of oil used will not be very great. Also the
pod for the batteries does not have to withstand the ambient pressure so
it can be made out of a lighter material and it does not have to be
cylindrical. I am planning on using mineral oil. If the
batteries need to be inspected or replaced then I would drain out the couple
of gallons of mineral oil at that point. Then refill the space with oil
upon completion of battery change out.
Brian