Re: (ET) desulfator

["David Roden" <etpost drmm net>]

On 17 Feb 2007 at 17:50, Neil Dennis wrote:

> My, My, that was quite a reaction (;-'). 

Sorry, I don't mean to be overbearing about this.  I've posted comments 
about desulfators many times before here, though, and didn't really say 
anything especially different this time (though I said it perhaps more 
succinctly or more bluntly).

Let's try it this way.

Suppose you're down by the dock, cussing about your boat's battery.  It's 
a 
few years old, and you're finding that it won't run the lights long 
enough.  
It's supposed to be a 120 amp hour battery, but you can use only about 30 
amp hours before the lights start getting dim.  If you try to run the 
trolling motor, the lights almost go out, and the motor barely runs.

I walk by and hear you complaining.  I stop and tell you, "You have a 
sulfation problem. I have a gadget that will fix that.  This is a 
desulfator.  It reverses sulfation.  It can recover some of your battery's 
old zip - not all of it, mind you, but some.  Now, if you'd been using it 
from the time the battery was new, your battery would still be almost like 
new.  Use it on your next new battery, and when it's this old, it will 
still 
be good enough to run your lights and motor."

It's a deal.  I leave with $69.95 in my pocket, and you have a nice little 
black box.  It has an AC cord and a wire with clips for the battery.  
There's a little blinking LED on it.  

I told you to hook this black box up to the battery and leave it plugged 
in 
for a few days, to get back some of the tired old battery's capacity.  And 
when you get a new battery, you should use it for 12 to 24 hours about 
once 
a month, to keep the battery in tip-top shape.

So you try it.  Lo and behold, you run it for 3 days and you now have 40 
amp 
hours.  You run it another 3 days and you have 50 amp hours.  Another 
week, 
and you're up to 60!

Ah, but it doesn't last.  A month later you're back to 25 amp hours of 
capacity.  So you bite the bullet and buy a new battery.  This time, you 
hook up my gadget once a month for 24 hours, just as I suggested.  When 
this 
battery is 3 years old, you have almost 100 of your original 120 amp hours 
of capacity.  It works!

What did it do?  

In a brand new battery, not all the cells are exactly the same.  There's 
always one that has a little less capacity.  Each time you charge the 
battery, that's the last one to get full.  Sometimes it doesn't quite get 
there.  If this happens too often, that cell really does begin to develop 
permanent sulfation, but that's not what kills it.  

The capacity of your battery is determined by that weakest cell.  When 
that 
weak cell goes dead, its electrolyte is essentially water.  Its internal 
resistance goes way up.  Even if the other cells still have some charge 
left, they can't push any decent amount of current through the resistance 
of 
the dead cell.  So you can't get much useful work from the battery.  But 
many times you keep trying to use the battery for a while.  It can still 
light the lights for some time longer, even if dimly. 

When you do this, you're forcing current through that dead cell.  This 
charges it backwards.  This is called cell reversal, and it's very 
damaging. 
 Repeated reversal is what really kills the cell.  Its capacity takes a 
dive, and now you have a 30 amp hour battery when it used to be 120 amp 
hours.

When you connected my "desulfator," it forced current through the good 
cells 
(in the right direction!) to give the bad one as much charge as it could 
possibly hold.  

You also helped the battery yourself, just by taking an interest in it.  
You 
cycled it more often than you usually did.  Exercise for batteries is like 
exercise for humans - it improves their stamina.  This helped to 
temporarily 
build up its capacity.  That's why it rose from 1/4 to 1/2 its new 
capacity.

But then you went back to your old usage patterns, and the battery went 
back 
to its old capacity.

In using my "desulfator" on the *new* battery, you were performing a 
regular 
equalization on the battery.  This kept the inevitable weak cell fully 
charged, preventing it from being reversed as frequently.  You kept the 
battery fit and useful longer.

So I sold you a gadget that fixed your "sulfation problem."  I told you it 
would reverse sulfation - and it did.  I told you it would give your 
battery 
more capacity - and it did.  I told you it would keep a new battery fit 
longer - and it did. You're happy, and I'm $69.95 richer.  What's the 
problem?

What I sold you was a battery charger with a blinking LED.  Did I cheat 
you? 
 No.  I said it would reverse sulfation, and that's exactly what a battery 
charger does - that's how a battery charges.  I said it would add some 
capacity to your old battery, and an equalizing charge applied with a 
battery charger will do that.  I said it would help a new battery last 
longer, and equalization applied at the proper intervals will do that, 
too.  
Equalization brings up weak cells to get the maximum possible capacity out 
of an old battery, and prevent damage to weak cells in a new battery.

I didn't make any claims about "crystal resonance," even though some 
desulfator adherents try to do that.  Here's one example : "A desulfator 
works by creating a resonance frequency that cause the sulfur ions in the 
batteries to dissolve back into the electrolytic solution of the battery."

An electrochemist - an engineer who designs batteries - will tell you that 
such claims are nonsense.  I suspect that the people who developed pulse 
desulfators years ago found that they helped batteries, and they groped 
around until they found something that seemed to explain (at least to 
their 
satisfaction) what the gadgets were doing.  

Desulfators have a small but very avid and vocal corps of believers.  And 
they are right, in a sense - the gadgets do work.  But so would a cheap 
little trickle charger, for about one-third the price.  Or the charger you 
already have.  

What I really sold you back there on the dock, for $69.95, was $19.95 
worth 
of charger and $50 worth of advice - that equalizing your battery 
regularly 
would maximize its capacity and keep it healthy.  

But you could have gotten that advice for free - right here, in any number 
of good battery books in the library or at the bookstore, or on the web.  

I sold you something you could have - should have - gotten for free.  Am I 
a 
crook, or an entrepreneur?

For years I've been asking folks who sell desulfators, and those who are 
sold on them, to perform a real test.  I want them to use two batches of 
essentially identical batteries, applying the desulfator to half and a 
decent equalizing charger to the other.  Treat the batteries exactly the 
same except for what's charging them, and see if one group behaves 
significantly differently.

I think that's a reasonable request.  It isn't 100% conclusive, but if 
their 
desulfator is really better than an ordinary charger, it should show up in 
statisically significant, consistently improved performance in the group 
treated with the desulfator.  

So far no one has taken me up on it.  Any idea why not?


David Roden - Akron, Ohio, USA

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