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Q & A: Heavy batteries and transformers

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Most recent answer: 07/13/2009
Q:
Why are car batteries, transformers and electric generators so heavy? Does this have something to do with the basic electronic configuration of atoms? Does this mean lightweight (and thus cheap) batteries are a pipe dream?
- Gayle Weber (age 49)
Broken Arrow, OK
A:
Almost all car batteries are of the lead-acid type.  Plates of lead and lead oxide are immersed in a solution of sulfuric acid.  The weight of the battery comes mainly from the lead, it's heavy.
The lead-acid battery is an old work horse, it was invented in 1859 by a French physicist Gaston Plante.  It's cheap and easy to build, reliable, and has a good power to weight ratio. Lighter weight batteries exist but tend to be more expensive.   There are vigorous research efforts under way trying to find inexpensive lightweight batteries for electric automobiles.

Both transformers and generators need strong magnetic fields to make them work.   The best and cheapest material for that is iron, and iron is heavy. 

LeeH



(published on 07/13/2009)

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