At 05:35 PM 11/1/95 -0800, you wrote:
>OK, I'll throw my hat into the ring on this one... The _real_ reason why you
>should store your batteries on wood or some other insulating material and
>not directly on a concrete floor is to insulate your battery both
>electrically and thermally from the cold, damp concrete.
>
>Visualize the following scenario:
>
>A long period of cold weather causes the concrete floor and the battery in
>direct contact with it to cool. When the weather warms up the cold concrete
>and battery are consideraby colder than the surrounding air and will stay
>that way for quite some time. This causes condensation to form on the
>exterior of the battery. The condensation creates a current path from the
>positive terminal of the battery to ground (the damp concrete) and the
>stored charge in the battery is slowly drained away.
Unfortunately, that isn't the way batteries work. They don't give a hoot
about ground. That's why you can hold on to the positive terminal of a
battery with no problem. It is only when you get between the terminals
(usually with a screw driver, or what use to be a screw driver) that you get
into trouble. The electron flow in a battery comes from a chemical reaction
inside the battery. When you charge it, you push the reaction one way. It
doesn't like to stay that way and will take any opportunity to return to its
resting condition by pushing the electrons back around the circuit. The
only discharge path would be either between the contacts of the battery, or
through an internal path as you find more commonly with NiCad batteries (as
it is their nature).
>Condensation will also
>cause a slight current flow between the terminals of the battery, but the
>negative post has a much smaller surface area than the contact patch between
>the bottom of the battery and the concrete so this has a lesser effect.
>
>Condensation will still form on the battery if it is on wood but the battery
>will warm much more quickly to the surrounding air temperature, allowing the
>moisture to evaporate and remove the current path between the posts.
I again ask the question, if this is all true, does that mean you don't have
the problem in desert climates, or during hot, dry weather, or clod dry weather?
It sure is amazing the way threads mutate and continue on, and on, and on...
The federal grant is sounding better and better all the time.
Ted Weiler
BSEE
Ph.D. Bioengineering
'74 MGB GT
Edward B. (Ted) Weiler, TWeiler@Eskimo.com, www.eskimo.com/~tweiler
Director, Volunteers NorthWest, vnw@aol.com,www.eskimo.com~tweiler/vnw.html
Membership, MG Car Club NorthWest Centre
mgccnwc@aol.com, www.eskimo.com/~tweiler/mgccnwc.html
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