Paul Harvey on batteries

[db (martinez, ca.)]

I was hoping that someone would comment on old Pablo's "news" show last week where he said that you can get some more life out of dead rechargeable batteries by banging the negative ends together a few times. Maybe i'm the only one here with this insidious radio vice.

Anyway; do you think this works? I hope it does, or i'll have to rethink everything else i learned from him.

[John Limpert]

I can't think of a reason why it would affect the batteries, for good or bad. All of the battery reconditioners that I've seen rely on charging and discharging the battery in a way that is designed to fix electrochemical problems inside the cells.

[James M. Prange (Michigan)]

Maybe it shakes some electrons down to the negative end, where they belong?

[I, Claudius]

It would do well to examine the source. While well-meaning, Paul Harvey is simply a radio commentator, an entertainer. He is by no means an engineer, or even a tinkerer. He makes his living with his mouth, not with any talent for technology. This particular claim of his is simply not substantiated by any evidence.

[Ron]

Try it and report back...

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[Dave Shaffer (Arizona)]

I suppose there's a small chance that just "banging" the batteries might help - regardless of polarity or direction, however. (I do like the suggestion that the electrons just need to be knocked back to the negative end!!)

Although you think of a battery as an electro-chemical system, there are also some mechanical factors involved. As the battery compounds are charged/discharged, they expand and contract slightly as their chemical state changes. This is what causes your car battery to go dead - some of the lead plates basically fall apart and short things out.

Think also of battery leakage. While chemically driven, there certainly are mechanical changes. Many batteries swell up as they die and leak.

I don't know about NiMH or NiCads, but I suppose there might be mechanical changes in them, too. So, a good bang might break up something that has gone wrong, such as dislodging a minor short circuit.

As Ron suggested, try it and see what happens!

[Paul Brogger]

I heartily recommend Steve's article -- non-leaking NiCds may be dramatically improved by the "zap" method.

But banging the negative ends together? I'd have to say:

Good Day?

[Les Bell]

There is a theory that, over time, NiCad cells develop conductive "whiskers" of some crystalline substance (not familiar with the chemistry, sorry) and that these whiskers progressively short out the cells, reducing their capacity.

The whiskers are fairly brittle, and the theory says that a mechanical shock can break them and restore the cell to higher capacity. (The same theory also explains "zapping" cells with a charged-up capacitor). Obviously, it doesn't matter what end of the cell you bang against another; it's the g's that do the trick.

Does it work? I tried it once - if memory serves correctly, on a battery pack for an iCom portable radio. I slammed the pack hard against a brick wall. It seemed to work, but some time later I had the battery rebuilt with new cells, so obviously the fix wasn't permanent or some other effect was at work.

Best,

--- Les

[http://www.lesbell.com.au]

[Hans-Erik Lehndal]

I read an article back in the 70´s about zapping life back to NiCd cells by using a (huge) capacitor, I think it was in Popular Electronics. While the idea seemed nice enough, I never succeeded in my revival efforts. Perhaps a bit of faith is needed too?