Re: [Paddlewise] Electric pumps

I've got my battery in a Tupperware freezer container, with the leads
emerging from two sealed holes drilled in the top.  Since we've had the
pumps, we have not found the container tops blown.  It may be that a small
amount of gas vented through the relatively low-pressure seal offered by
this container, but there's no evidence of that.

I gather that most (if not all) of the gas-venting will take place as the
battery discharges.  In that case, I think it's important to remember that
the battery is not likely to be discharging for very long periods.  After
all, it empties a cockpit in about four minutes.  But if venting does take
place, then it makes sense to use either a low-pressure container like I use
or a vent plug on a more sturdy container.  Another preventive measure might
be to pop the hatch and the battery case cover at the end of each day.  I
generally take the batteries -- case and all -- out of the boat on days when
we're not paddling.

As for electrolyte leaking through a vent hole, I'll take Jack's word for
it.  We've had the batteries installed during rolling practice and, again, I
never noticed any evidence of a leak.


From: JCMARTIN43_at_aol.com <JCMARTIN43_at_aol.com>
Date: Friday, April 07, 2000 10:12 AM
>...in discussions with the manufacturers of my lead acid battery, a point
was made that these batteries will vent a toxic gas --- hydrogen sulphide, I
believe --- when they discharge.  The manufacturer strongly recommended not
placing his batteries in a drybox; in another application, a rescue service
placed a battery for a piece of emergency gear
>--- probably "jaws of life" --- for use in a marine environment, and the
box exploded, causing some minor damage.  Now, that apparatus could well
have drawn the battery down very quickly, causing more than average venting.
But it could still happen.  In fact, this manufacturer didn't even like the
idea of carrying the battery in the sealed after compartment of a kayak.
>
>Take this for what it's worth.  On a personal basis, my plan is to install
the battery in an old Pelican box, but install a blow-out plug with some
silicone adhesive to give the box a safety valve.  What will happen inside
those nice, tight Valley hatches is another matter.  But it's worth thinking
this through a little.
>
>Jack Martin
>


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