AUTHOR REPLIES TO YOUR COMMENTS - wire inside car battery cell

Hi guys
I am the OP of this thread about testing a car battery by putting wires into the cells.
I originally read this at About.com and I figured I should point
out the clear warnings of how dangerous it is which many of you gave me and mention them to the author. I did that.
The reply I got from the author says he stands by what he wrote. See text below.
The author is saying that the procedure is safe although it needs protective clothing
I wonder if the Usenet posters here who were very concerned about the method would like to comment on this.
JS
My question and the answer can be found at: http://autorepair.about.com/library/a/1i/bl670i.htm . For convenience, here is a copy of what is there:
------------------- START QUOTE -------------------
Dangerous Battery Testing Advice????
Q. I read an ABOUT.COM article at The Charging System See below the text in question on this web page. I am told by many people that what you advise is highly dangerous and quite likely to lead to serious injury. Please see the very recent newsgroups thread at "Put wire inside car battery cell to measure voltage?" Dated Nov 25, 2006.
I feel I should report this to you as it would remain on my conscience if someone got very badly injured and I was aware of the possibility but had not informed you. Would you be so kind as to review the contents of your web page to see if it is unsafe.
Thank you, John S.
-------
A. I was the one who wrote that article and described the test procedure you quoted. It is a standard and legitimate test of a batteries cell condition. In my youth when I took my auto electrical courses, it was taught as part of the curriculum. I have even seen it taught in factory training classes.
And if I remember correctly, it used to be on the NIASE certification tests.
Of course you do need to take the normal precautions when you do any kind of battery testing and servicing such as wearing approved eye protection and acid resistant clothing and gloves and working with adequate ventilation. But when done properly, it is a safe test to perform.
After reading the entire thread you point out, I have my doubts about some of the "many peoples" ability to check the air in a tire, much less offer advice on something they know nothing about.
Bottom line is: it is a valid testing procedure and I stand by what I wrote.
------------------- END QUOTE -------------------
Alternate route to this. Go to the General Q&A folder at http://autorepair.about.com/library/a/bl_q&a.htm . The entry is on the Last Page or second to Last Page.
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Frankly, there are some real hazards with this idea.
If the plates are uncovered, and your iron wire happens to short between the plates, a spark could ignite flammable H2. To avoid this, it would be necessary to insert the rod first, before connecting the other of the rod to the meter.
Even if the plates are covered, your wire could still short the plates. Or push the separate down to the point where the cell developes an internal short sooner than it might otherwise. Pushing the wire down between the plates, you have a good chance of scraping material off of one plate. If not retained by the separator, it could fall to the bottom and short the cell.
If you're just touching the tops of the plates, then you probably won't *mechanically* damage the cell (unless you happen to ignite some H2).
In larger stationary batteries, and submarine batteries, the electrolyte is sampled and chemically tested periodically. One of the contaminants that warrants replacing the cell is if there is *iron* contamination. Yet this procedure will do exactly that, contaminate the cell with iron.
If one *really* must put an electrode down into the acid of a cell, use a lead coated one. We've used probes explicitly built for this purpose. The lead will not contaminate the acid, and the resistance of the probe is not important if using a high quality digital voltmeter.
Measuring the individual cell voltages (ICV's) is a common practice for larger battery banks made up of individual cells. It can be used as an indicator of failure. Often a single bad cell can be removed and jumpered around, restoring the rest of the battery to service.
But in smaller molded case batteries, it's pretty much a mute point. If the cell is bad, the whole battery must be replaced anyway.
daestrom P.S. The author can 'stand by' it, but I won't stand near him when he does it. I don't think you'll find any major battery manufacturer that will go along with it.
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I suspect the answer to this is simple. The original poster of the article is old :) Many things that were taught and regarded as "safe" as little as 20 years ago are now regarded as not safe. Benzene used to be used in school chemistry labs 30 years ago - I would be surprised if you could find a bottle of benzene in a school lab today. :)
Add to that what someone else has said about having to replace the whole battery anyway if one cell has gone (for the modern plastic extrnal wet cells used to start cars) and there is no real reason to test the individual cells. Either the thing works or it doesn't. If it doesn't the worst that happens is you spend $70 on a new one. The worst that happens if you screw up the sort of test you are talking about is that you splatter yourself, your surroundings and anyone nearby with fairly concentrated sulfuric acid and suffer hydrogen burns. I'd rather spend the $70 :) :)
HTH
Bruce
---------------------------------------- I believe you find life such a problem because you think there are the good people and the bad people. You're wrong, of course. There are, always and only, the bad people, but some of them are on opposite sides.
Lord Vetinari in Guards ! Guards ! - Terry Pratchett
Caution ===== followups may have been changed to relevant groups (if there were any)
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On Mon, 05 Dec 2005 00:23:59 -0000, Bruce Sinclair

That's the point, you're not going to find out anything usefull or relevant.
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