Worldly Scions,
Late digester here on the trailing edge of the thread.
Mark Clark wrote:
> Although I was not able to find it on the Urban Legends page, I also seem
> to recall that the old addage about car batteries and concrete floors had
> to do with older batteries having cases covered with tar. Why that makes
> any difference I can't for the life of me remember, and since I couldn't
> find a reference to it anywhere, it's probably just something I learned in
> a dream.
I think I had that same dream. ISTR that the problem was the
temperature
gradient. Older (tar covered?) batteries had less durable cases and a
flatter bottoms (i.e. no feet or ridges to stand on).
Picture a black battery sitting on the ground in the morning sun, after
an especially cold winters night. Most of the battery could get quite
warm, but the bottom being in intimate thermal contact with the ground,
remains very cold. This could give rise to stress cracks around the
base
of the battery. Especially if this thermal cycling happens repeatedly.
Most unpleasant when the battery is finally lifted from it's resting
place.
Not a problem today thanks to modern plastics.
Then again, maybe it *was* just a dream?
Bob (& Spitfires)
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