Put wire inside car battery cell to measure voltage?

[John]

We were somewhere around Barstow, on the edge of the desert, when the

drugs began to take hold. I remember JS

Yes, and another handy tip if you can't see how far down to insert the
wire use a lighted match. The flare of the striking match gives off
better light than using a torch. Do let us know how you get on.

 

[Chris Street]

As apprentices we pratted about and wrapped solder around the live and
neutral pins of a plug then plugged it back into a switched off socket.

*Huge* flash when it was switched on. The solder vaporised almost instantly
but the shock value was amazing.

Would never do that sort of thing now though.

A good way to demonstrate the high instantaneous current capacity of Nicads
is to get an AA or even AAA Nicad and short it out with solder - again it
vaporises immediately, but a bit less spectacularly.

I've seen the results of a Stilson being dropped accidently on a 24V lorry
battery assembly. It flashed and welded the Stilson on, and it was too damn
hot to get off within a few seconds so we just watched it until it went red
and the battery posts melted off.

The amount of energy a good lead acid can deliver is quite frightening.

 

[Dimitrios Tzortzakakis]

--
Tzortzakakis Dimitrios
major in electrical engineering, freelance electrician
FH von Iraklion-Kreta, freiberuflicher Elektriker
dimtzort AT otenet DOT gr

That's good! (No, I hadn't seen it.)

That reminds me of my army duty, when we were practicing tossing grenades,
and someone was doing it particularly badly (note we were using
"training"grenades, also only with a noise fuse and not real TNT)and the
sergeant told him, if you do that son in the fire range and see everyone
running, you will understand you have done something wrong.

 

[Dimitrios Tzortzakakis]

--
Tzortzakakis Dimitrios
major in electrical engineering, freelance electrician
FH von Iraklion-Kreta, freiberuflicher Elektriker
dimtzort AT otenet DOT gr

I've seen the results of a Stilson being dropped accidently on a 24V lorry
battery assembly. It flashed and welded the Stilson on, and it was too damn
hot to get off within a few seconds so we just watched it until it went red
and the battery posts melted off.

The amount of energy a good lead acid can deliver is quite frightening.

And we had some (bad) students in college who were trying to measure voltage
with an ammeter..or with a multimeter turned on the ampere rating.I don't
know if they made it got a degree and became electricians though.Or they
made a (simple) automation circuit all right and when the professor came and
they pressed the button to start the automation the result was...bang!

 

[Malc]

I've seen the results of a Stilson being dropped accidently on a 24V lorry
battery assembly. It flashed and welded the Stilson on, and it was too
damn
hot to get off within a few seconds so we just watched it until it went
red
and the battery posts melted off.

The amount of energy a good lead acid can deliver is quite frightening.

A friend of mine welded the links on his watch strap together helping me
with a head gasket once. He managed to short the feed to the starter
solenoid.

--
Malc

"The error of youth is to believe that intelligence is a substitute for
experience, and the error of age is to believe that experience is a
substitute for intelligence."
- Slyman Bryson

 

[Guy King]

The message <[email protected]>

A friend of mine welded the links on his watch strap together helping me
with a head gasket once. He managed to short the feed to the starter
solenoid.

To think - I used to dismantle lead acid batteries in my early teens to
provide 2v cells for starting glowlug motors.

I also found that with the carbon rods from zinc-carbon batteries, some
wire and a car battery I could melt common salt with the arc, from when
on it became conductive and could be kept glowing orange for ages.

 

[Steve Firth]

A friend of mine welded the links on his watch strap together helping me
with a head gasket once. He managed to short the feed to the starter
solenoid.

The bloke wot repairs my tractor tends to treat me like someone who has
never seen a spanner in his life. It's like working on a car with my dad
around, lots of teeth sucking and use of the word "don't" while working.
Last time he was working on the hydraulics and I noticed the battery
terminals were loose. So I got a pair of 13mm spanners and started to re
tighten them. He noticed what I was up to and gave me a big lecture
about the dangers of working with spanners on the battery (both
terminals are close together). Then he decided to take over and show me
how the experts do it. First attempt he dropped the spanner across both
terminals, huge flash, he tried to stand up but had his head under the
hood. Bang, <****>.

He looked around and I was lying on the floor PMSL.

He was very good about it, bought me a brand new battery.

 

[Chris Street]

The message <[email protected]>


To think - I used to dismantle lead acid batteries in my early teens to
provide 2v cells for starting glowlug motors.

I also found that with the carbon rods from zinc-carbon batteries, some
wire and a car battery I could melt common salt with the arc, from when
on it became conductive and could be kept glowing orange for ages.

It's nice to know it's not just me tried that trick....

I used to intially melt it with a gas torch though, then see if it could
electrolyse it and evolve green gas....

 

[Guy King]

The message <[email protected]>

I used to intially melt it with a gas torch though, then see if it could
electrolyse it and evolve green gas....

Stunk a bit, didn't it. And stung the eyes. Never managed to get
recognisable sodium on the other electrode though.

 

[PC Paul]

before 1.) i would make sure that the cells' water level was up to
proper level.

Seconded. I recently topped up my dying-on-cold-mornings battery with
de-ionised water, jump started it, went for a drive and all is well now for
several days.

 

[JS]

On Sat 26 Nov 2005 21:02:15, R. Murphy wrote:

If you want to measure the voltage, use a voltmeter on the
regular terminals. If not up to par, then it needs charging. If
it won't charge up, then it doesn't matter which cell is faulty,
since you can't replace all of them.

If you do want to check the electrolyte level/strength, buy a
hydrometer.

Or alternatively, stop winding us up!

No wind up mate. I was asking about what I had read at:

http://autorepair.about.com/cs/electrical/a/aa090303a_2.htm

 

[daestrom]

As a young kid at school I decided that a bit of wire in the live and
neutral points in a socket would be a good idea because the current would
just flow along it. I even managed to convice a couple of mates, and tried
it to prove the point.

The resulting flash and bang scared the shit out of me, along with the
rest of the *German* language class lol...

When I was about four, I discovered that your average staple from an office
stapler would fit in a conventional 120VAC outlet just fine. The resulting
sparks and flash scared both me and the dog (when I jerked my hand away, the
remains of the staple landed on the dog).

Poor Petey (the dog). He was *always* afraid of lightning and thunder after
that. ;-)

daestrom

 

[Herman Family]

When I was about four, I discovered that your average staple from an
office stapler would fit in a conventional 120VAC outlet just fine. The
resulting sparks and flash scared both me and the dog (when I jerked my
hand away, the remains of the staple landed on the dog).

Poor Petey (the dog). He was *always* afraid of lightning and thunder
after that. ;-)

daestrom

Sometimes its amazing to realize that we actually survived our childhoods
without all the current safety devices. I'll refrain from any stories, but
will say that this is on par with a few of my experiences and those of folks
I knew back then. Many (or at least a few) of them are still alive and
mostly well, or as well as could be expected. Come to think about it, there
were a few who left the gene pool early.

There is something attractive about those little tiny holes in the wall
which contain something that makes things run....

Michael

 

[JS]

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.

 

[daestrom]

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.

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.

 

[ehsjr]

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

Why do you think test probes are insulated?
Is a coat hanger insulated?
Making any measurement with uninsulated conductors
introduces a risk. Do you want to be holding a
red hot coat hanger?

Ed

 

[Tzortzakakis Dimitrios]

Why do you think test probes are insulated?
Is a coat hanger insulated?
Making any measurement with uninsulated conductors
introduces a risk. Do you want to be holding a
red hot coat hanger?

Ed

Or just be eligible for the next face transplantation...

 

[Duncanwood]

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

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

 

[Bruce Sinclair]

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.

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

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