> The part that bothers me about it is the idea of connecting all of these
> in parallel,  I keep thinking that there ought to be a better way.  Some
> sort of a circuit to sense voltage and charge them independently,
> perhaps,  or something to switch out a unit that shows a *really* low
> voltage (like the one here that's down to around 10v or so,  may be a
> shorted cell),  something like that.
 
> I've been idly thinking about how I might set such a thing up,  but
> haven't arrived at anything yet.  Care to comment?
 
Ought to be able to do something like that with a transistor pretty
easily. You say you don't like parallel circuits and the transistor
ought to do better in a series circuit. All the transistors would end
up being in series too. One across each battery so that the transistors
are in series with each other but parallel to each battery. Conversely,
all the batteries would be in series with each other but in parallel
with it's individual transistor. The major problem would be that when
the battery went too low in voltage turning on it's transistor and
thereby shorting out the battery, the transistor would then have to
carry an increased load. If all the transistors were turned on and
shorting out all the batteries then you would end up with a dead
short across the line which would have to be prevented somehow.
 
Even if it worked, it could be a real headache.
 
I have been doing a bit of experimenting. I got me two pounds of the
EDTA compound. It's a powder that is totally insoluble in either
acid or water. I did 12 batteries with the EDTA and put them on to
charge. These were all total junk batteries that I was ready to haul
off to the scrap yard because they would not charge. One of the 12
junk batteries refused to even start charging at all. Totally dead.
So dead that I put the full voltage of my charger right across the
two terminals. That would put approximately 65 volts of D.C. right
across the terminals and it did nothing at all. If I did that with
any "normal" battery, sparks and smoke and fire would be flying all
over the place. So I took a chop saw and cut the top off of it to
see what I could see. Then I refilled it with acid and hooked it
to a regular battery charger for a few hours. Nothing at all. I
could make one or two of the cells charge a bit by hooking the
positive lead to the positive post and the negative lead to a
welding rod and touching the two bars moving back from the positive
post one cell at a time. You could see a little charging going on,
but it wasn't enough to measure even with a milliamp meter.
 
My next trick was to dump in a product made by Exide which claims
to have cadium sulfate in it. Hooked the battery charger up to the
battery with exactly the same results. ZILCH. So I reversed the posts
on the battery hooking them up backwards. That's when the fur started
to fly. First one or two of the cells started smoking a bit and then
they started sparking somewhat violently for a moment or two. Then
they quieted down and the charging current started to come up. Came
up to about 10 or 12 amps. I let it charge backwards for about 10
minutes and then reversed the leads again, pos to pos and neg to neg.
 
The same cells started the arcing again and smoke came up out of the
liquid and then it settled down to charging. I let it charge for
another maybe 10 minutes and reversed them again. This time the
charger's ammeter pegged for a minute or so and started coming back
down to a more normal 8 to 10 amps. When it did that, then I reversed
back to the normal hookup and after a couple of minutes it was back
to charging it's 8 or 10 amps again and I've left it for the night.
 
So we will see what happens, but right now it looks like the durn
thing will charge normally now. I don't know if the chemicals had
anything to do with it or not or wether it was just the reverse
charging that did the trick. I will most likely grab me up about
8 or 10 more junkers tomorrow morning and set them up for a normal
charge but reverse the leads for a few minutes at first. Then I will
reverse the leads again and make them charge in the normal manner
and see what the charging current looks like then.  Of course it's
also critical to see if the voltage on each battery will do when
they have been charging normally for an hour or so.
 
I don't know how much good either the EDTA stuff or the cadium sulfate
will do as of yet. I guess I would have to try some junk batteries
with each separately and then some with the two chemicals combined
to find out. The EDTA will most definitely revive a few batteries,
but from my standpoint I also have to look at how much work it is to
apply as well as cleaning up the mess afterwords. That all costs
work and time which is money. Unless the EDTA will revive a huge
percentage of my junk batteries, it would not be worth the cost
of both time and material. So far, I don't have sufficient positive
results to justify the extra work, let alone the extra investment
in chemicals. If the trick of reversing the direction of charging
a couple of times will work all by itself then the cost of the
chemicals would most definitely not be worth it.
 
All I can say at this point is that it's going to take a lot more
experimenting before I can come to any conclusions about this EDTA
stuff. Somebody said they had paid $15 or so for enough to treat
one battery. That's a terrible rip off since the stuff only costs
about $1.76 per pound in 100 pound drums. I know for sure it wouldn't
be worth that kind of money to pay for about a 25% chance that it
might salvage one's battery. If it didn't do it, then you would have
to add the $15 to the price of the new battery you also had to buy
and then it would be expensive.
 
If the EDTA would salvage 50 to 75 percent of the batteries I would
otherwise junk then it would be well worth it and if it don't do that
then it isn't going to be worth me fooling with it and it would only
cost me about 85 cents or so per battery.
 
Bill Bauer
--- DB 1.58/004358
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