Car Batteries

Batteries today are typically collected for “recycling” and shipped off to a battery recycler. Is this the best way to handle batteries? Is there a way to reuse them for a longer time, that can be applied by an individual customer or, at least, a local rebuilder?

Batteries today are most often made of formed lead plates sitting inside a black, square box made of acid-resistant polypropylene. The box is filled with a weak sulfuric acid solution which bathes the plates. When the battery is charged or discharged, the lead plates react with the sulfuric acid to make lead oxide or lead sulfate. When the recycler gets a battery, he drains the acid and cuts off the top of the black box, thus destroying it. He probably sends out the plastic pieces to be ground up and re-extruded into a new box. Why, I ask you, would anyone destroy a plastic part that seems perfectly usable in order to make a new part? Can we make the part even more “perfectly reusable”?

Today in this risk averse world, practically any chemical is considered too dangerous for ordinary people to ever encounter. Even thinking about chemicals makes Jimmy Six-Pack shrink in horror. But it wasn’t long ago, let’s say through the seventies, that anyone and everyone was expected to add water and acid to the batteries in their car. I would argue that ordinary people are perfectly capable, with a little training or instruction (not the same thing as dire warnings) to handle what I propose here.

The thing that goes wrong with batteries is most often that the lead anode or cathode (the plates) loses its shape. It crumbles into powder or falls off the electrical contact to the outside so the chemical reaction that constitutes charging doesn’t work any more. What is the natural repair? Why open up the box, remove the acid temporarily, replace the lead with new plates, put back the acid and close up the box.

In order to make this simple, we need to redesign the box so it is easily opened. How about making it in two parts, a deep box with a flange around the top and a cover with a matching flange? Opening up the box would then consist of opening up the fasteners holding the two flanges together and lifting up the top.

There are three major internal parts in a lead acid battery (with lots of minor variations). But if the top of the box were easily removed, and the connections from the outside posts to the plates inside were simplified and standardized, then almost anyone could rebuild a battery, or build a new one, just by buying a kit with the plates. There is one plate that is covered with solid lead dioxide. There is another plate that is made of a spongy lead. There is the liquid, or electrolyte, of weak sulfuric acid, which bathes both. Unless the electrolyte has an additive making it into a gel (so that no spillage can occur), that’s all.

It would be good to redesign the plate attachments so that residual lead sulfate or oxide could easily be removed, the plates easily removed from their contacts and new plates easily reconnected. I leave that as a homework problem for battery designers. Then we need to create the position of local lead collector to collect the lead powders or plates and supply new ones. When he got a truckload together he would ship the lead to a smelter. Meanwhile he could open up a battery that was brought in, pour off the electrolyte, remove the old plates, put in new parts and hand the battery back to you, good as new (and much cheaper).

Some people may object that battery recyclers invariably throw lead contaminated sulfuric acid all around, contaminating the ground and ending up as Superfunds. Possibly true, for a few plants, but this is a defect, not an insoluble design flaw. There is no reason for a battery plant to leave one drop of sulfuric acid on the ground. A chemical processing plant can be much better designed than that so long as gross profit is not  allowed to be the sole, unique goal.

Lead-Acid batteries often fail because as they charge and discharge, the plates change from one chemical compound to another (mostly to lead sulfate) and this creates mechanical failure where some of the lead or lead compounds flake off or fall off the plates onto the bottom of the case. One way to repair a battery IF IT COULD BE OPENED would be to remove the free powder and pieces from the bottom of the case where they cause spurious short circuits. Today, this is not a conceivable repair.

Even if the battery went to a standard recycler – like we use today – he would not have to cut open any box but would be able to remanufacture the battery from the old box.

So often, expensive, wasteful methods are put into place in order to wring extra cash from customers who must then be kept in the dark as to what goes on behind closed doors. Standardization, modularization and easy repair will work for chemical processes as well as for mechanical manufacturing.

(Stay tuned for a discussion of lithium batteries which are becoming standard now)