Had been using commercial unit by Innovative Energy that uses "sweeping pulse" technology. Unit was externally powered by wall wart so was usable on several voltages of battery. Unit worked very well until I HOOKED IT UP REVERSE POLARITY and released its built in smoke packet!
I reclaimed 60 or 70% of the 6volt deep cycle golf cart batteries that I tried it on. Most of them had been sitting over a year after being diagnosed bad (after 18 month
service in rental platform lift).
The unit used 10khz--100khz sweeping frequency or so it claimed. I never had the opportunity to measure the output unfortunately.
I am hoping to build a unit to duplicate or better that performance. Has anybody heard of them?

 

You can use some variant of this circuit here http://home.comcast.net/~ddenhardt201263/desulfator/n_channel_schem.gif
I also guess you do not understand quite how the circuit works. So you should read how it works here http://home.comcast.net/~ddenhardt201263/desulfator/lowpower.htm
To make it short the circuit produce a high current spike repeated with a 1KHz rate. It is this spike that causes the desulfation. I guess the desulfator may work faster with i higher pulse rate. But it is a limit here. And that is how fast you can charge the capacitor C4 in my schematics link. Then another thing is how wide the current pulse is. It is said to 100uSec wide. I do not know fast you will be to generate the spikes.

 

Welcome to AAC.

I moved your post to its own thread, as it is not very related to the one you posted in - http://forum.allaboutcircuits.com/showthread.php?t=23695

 

Do you have a digital camera?

It would be helpful if you could post images of the original circuit board. Perhaps it could be repaired.

 

The unit used 10khz--100khz sweeping frequency or so it claimed.
I am hoping to build a unit to duplicate or better that performance. Has anybody heard of them?

According to this thread 10K to 100Khz is not effective >> http://forum.allaboutcircuits.com/showthread.php?t=23695

they state it should be more like 800Khz......

But I have also read some where that it should be around 2 to 4mhz.....

I would actually like to know the freq yours was running at, since you said you have had good experience reviving desulfated batteries back....

I have a 555 based circuit that was supposed to connect in line with a charger.....

Maybe it would work, maybe it won't but I have not even tested or prototyped it yet...... Maybe Sarge can run it through one of his sims....

 

As mentioned before I not think the charge and discharge cycle will allow 800KHz, but feel free to prove me wrong

 

I can't see that the frequency would have much to do with it.

*Maybe* there is a mechanical resonance but that will be due to plate size and mounting and will vary greatly between battery types and sizes. And it would be in the low kHz.

The old timers thought that 100 Hz worked pretty good. And they were just crude SCR switched full wave chargers, usually with a car headlight etc wired across the battery.

 

I can't see that the frequency would have much to do with it.

*Maybe* there is a mechanical resonance but that will be due to plate size and mounting and will vary greatly between battery types and sizes. And it would be in the low kHz.

The old timers thought that 100 Hz worked pretty good. And they were just crude SCR switched full wave chargers, usually with a car headlight etc wired across the battery.

The desulfator produce a high voltage current spike. It is about 5 Ampere at max. The voltage from a unloaded desulfator is about 80 volt. So it will give the battery a real kick.
Most of the car battery charger I have seen is quite simple. A transformer and a rectifier.