Why Are Automobile Batteries So Heavy? Why Can’t They Be Miniaturized?
Good question; simple answer. When one shoves his mother-in-law’s car into the lake, (with her in it), one needs the weight to insure the car doesn’t float! Okay, okay. I’m just kidding.
It would be nice to have some small, rechargeable, battery so you could carry two around in your glove box just in case the one under the hood decides to roll over and die… but it isn’t going to happen any time soon.
First and foremost, as Stephen Bomer of the Automotive Battery Charger Manufacturers stated, high density lead plates are a major component of a battery: "No substitute for lead has been found that can do the job or generate the voltage required.”
Some batteries have been reduced in size over the last 20 years but according to H. Dale Millay, (a staff engineer for Shell Oil); we have paid the price for the downsizing. The greater the surface area of lead in the battery, the easier it is to generate power. Although modern batteries are good at cold starts, they have low reserve capacities.
As John J. Surrette, vice-president of Rolls Battery engineering, put it:
“The thinner you make the plates in a battery, the lesser material inside… The heavier the material, the more rugged the battery and the longer they will last. When you use thinner plates… this lessens the amount of ampere-hour capacity. When heavier material is used, like we do in marine and industrial applications, it results in considerably longer life and less exposure, (to the elements), which reduces the chance of the plates buckling in hard service or the active material shedding from the positive grids.
…Miniaturized batteries would probably be preferable but would stand little or no abuse or neglect.”
I can’t say that I completely understood everything Mr. Surrette said, but it seems to make sense. But I still prefer the way David Feldman said it: “The car battery is one case where you don’t want to get the lead out.”
(I will thank David Feldman, and his book, “Do Penguins Have Knees”, for the information on this subject.)
