Mechanics are taught to keep batteries off the floor.

Dear Car Talk

Dear Car Talk | Nov 01, 1991

Dear Tom and Ray:

This may sound like a dumb question, but maybe you guys can answer it and settle an old feud I'm having with several friends. Back in the sixties and early seventies, I worked in several service stations and repair shops. At these places, we had battery chargers. The owners would always set the batteries on blocks of wood or on a table, never on the concrete floor. They insisted that the batteries would lose their charge if set on the floor. Is this true? How could this be?

TOM: Great question, Mark. This is the story to the best of our knowledge. Many years ago, battery cases were made out of wood. And the theory was that if the battery was left on a damp, concrete floor, the moisture from the concrete would act as a conductor and drain the charge from the battery through the wooden case.

RAY: Of course, this doesn't apply to modern batteries, because they've been cased in plastic for decades. Nonetheless, mechanics are still taught to keep batteries off the floor. But that's just so they won't trip over them.

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