Preliminary article Created: "March 6 2009"
My Latest Revision: "June 6 2009"

This Circuit helps to Desulfate a lead acid battey.
It also gives a fair indication of the batteries Internal Resistance.

NOTE: Some Batteries can be Improved, Some NOT.
Sulfated Plates is only One of Many different battery problems.
So it all depends on whats wrong with your battery?


This circuit produces a Pulse Current Spike to help Desulfate a battery.
Additionally, the other part of this circuit detects this Pulsed Current Spike,
"Directly At the Battery Terminals".

This signal is than amplified and gives a reading on a 200 uA Meter.
And this reading will reflect on the Internal Resistance of the battery,
So the "LOWER the meter reading the better".

Sulfation Causes Higher Internal Resistance and Internal Resistance in a Battery
Reduces its ability to drive High Current.



In Theory, with "Unlimited Sensitivity", and with a "PERFECT Battery", the meter
reading would always read "ZERO".
However, This will NEVER HAPPEN on a Real Battery.

And in real life, Smaller Lead Acid or Sealed Lead Acid Batteries will have Higher
Meter Readings than Large Car Batteries.



This Desulfating Process,  "May take a LONG TIME".
This Process may be anything from a "Day or Two" for just General Battery Maintance,
and up to "Several Months for a really Bad Sulfated Battery".

And the battery MUST have a Reasonable Charge on it for this Desulfator to work.

Failing to Maintain a Charge on the battery, can be solved by connecting the battery
to a Solar Panal or a suitable DC Supply of about 14 Volts "Via a Series Resistor".
I would recommend a 10 to 20 Ohm Resistor.

This SERIES Resistor is IMPORTANT, to Prevent the "Charger's LOW IMPEDANCE", from
Absorbing the Desulfators Spikes, Thus stopping these spikes to Desulfate the Battery.

** This Desulfator Circuit can deliver pulses of 6 amps to the battery,
but it ONLY Draws about 100 mA, Average Current. (0.1 Amps)
So When charging While Desulfating, the actual charge current can be quite low Also.



If you have Two Batteries of the same A/H Rating and Size and both Fully Charged,
you can set the Sensitivity control to give a specific reading.
(Possibly a 100 uA reading on the first battery.)

Than Without changing the sensitivity Control, connect this unit to the second battery
and get a Comparative Test Reading.
The Battery with the LOWER Reading, Will be the Better Battery.



NOTE: The Range of Adjustment for this Sensitivity Control was "Arbitrary"
determined by me.

** Since I Didn't have a "NEW, EXCELLENT QUALITY, BIG Car Battery", this Range of Gain,
was just a Guess on my part, "Based on tests, using Batteries I presently have".
And so far it seem to be a Good Adjustment Range.

However, IF in the future, I find More Gain is Required to Properly test LARGE Batteries,
The 100K Pot can be Increased to a 250K pot, to get considerably Greater sensitivity.

Doing further testing, I find that the 100K pot is Basically Satisfactory.
It won't show a reading on a GOOD 12 Volt Car Battery, But it Will show a
reading on Batteries that do have a problem.

If you want the Greater Sensitivity, Just Increase this pot to 250K.

NOTE: On this Prototype, I just used a Trimpot control. However, you can put this board into
a suitable box and use a Convential Potentiometer For Better Ease of Adjustment.




Go Back to My "Projects Page"


The Schematic"
This is a Revised Schematic & Parts List.


A "PCB" With an Actual Fuse.
This PCB Design uses a 500 MA. European fuse with on board Fuse Clips.
In my opinion, These Fuses are Better & definately Smaller than the standard AGC Fuses.

Overlay Picture.
This picture shows a Resistor instead of a Fuse.
A Revised Picture will be coming soon.

This Article is "Subject to Modifications"

All Imformation in this Article is "Copyright protected".

 Chemelec 
 *Copyright © 2009*