A strange tale: For the heck of it, I pulsed a spanking new group 65 starter battery for a friend and recharged it back to approximately where it was when he brought it over (12.75v). After resting, I applied a 50 amp load tester to it twice for 10 seconds. The first test removed the surface charge. Even with the second test, the voltage needle on the meter hardly deflected....It should have dropped a volt or so, even on a new battery.

It took a couple of more load tests to get the needle to substantially deflect. On a good battery, after a heavy load, the voltage should slowly climb back up as the plates chemically react and the plate gas dissapates; It takes a minute or so. That is why, when your starter on your vehicle starts dragging, for whatever the reason, let the battery rest for a minute....You'll get that final extra "boost" that will kick it over fast enough to start and yet still have enough juice left over to give a hot enough spark to get it to fire up. It's better than walking or waiting for a jump.

Anyhow, I cannot state why the battery was puting more than a new battery should, but it did...This battery was acting more like a much larger Group 31 heavy truck starting battery. Go figure.

On a real nasty, heavily sulfated battery, whose cells are not shorted out (rare), I usually use EDTA+....with mixed results, I may add.

These are the ones that have swollen plates caused by the sulfate buildup. Normally, when they get this bad, the plastic seperator gets perforated and the cell shorts out (nobody can fix it at this stage). This is different from a short caused by the build up of debris on the floor that reaches up and shorts the plates out; Dumping out the electrolyte and rinsing out with distilled while vigorously shaking the battery, then adding fresh electolte, will sometimes work. It will add muscle mass and pain to your arms, though.

I have found that most of the time, when the sulfate crystals are removed and the swelling decreases, some of the cells will short out. I guess that the damage was already done on the cell's plastic separators before any desulfation was attempted. The sulfate crystals, which act as insulators between the plates, when removed, cause the plates to short. I can always tell this when desulfating, because as the battery increases in power during the load tests, all of a sudden when you are reaching 13+ volts, resting voltage, a hard short will occur. I've had this happen with the pulser, as well as the EDTA. It just occurs dramatically more rapidly with the EDTA. Probably 4 out 5 really nasty ones are a waste in time. It doesn't really matter, since they were destined for the recycler's heap anyhow.

The bottom line is, don't wait until the battery is a basket case. Catch it early and save it every time. It's nice to have a starter battery live 8-10 years instead of 24-36 months (regardless of the warrenty). Deep cycle batteries can live much longer and give full power, until the plate gives out, instead of being junked for sulfation.

A great site...The prices are excellent, even considering the exchange difference between pounds and dollars. I am quite familiar with the design...Those are basement bargain prices for an excellent product. I'd buy them and ship them in; They're worth it, considering the low powered commercial junk out there...

My recommendation:

I'd order the "High Power" version only. The thermisters are necessary to keep from cooking the components, since sometimes runaway current has been a problem with earlier versions of Alastair Coupers base design.You had to watch the earlier versions like a hawk to keep from cooking some parts. Since they are hooked to batteries that are not static (the battery's stats change as it desulfates), the earler versions of pulsers could not regulate themselves. The alternative was to detune them down or regulate them. These are more akin to Farraris than mass-produced Ford Pintos. If not right on, they blow themselves up. But then, I'd rather have a Farrari anyday over a Pinto. You want to pulse a battery in days, not months.

Some easy and very useful changes: I'd definely change out the lead based battery terminal post clamps for large spring loaded "jumper" type clamps. I'd also use a much heavier, fine wire copper cable. 10 AWG minimum; I've seen some guys use 4AWG. Since a properly designed pulser has a signal spike that has an extremely fast rise time, the signal tends to act like a megahertz signal instead of a kilohertz signal. Such high frequencies, like RF frequencies and unlike DC current, tends to travel on the outside skin of the cable and not in the interior of the wires. With small diameter copper cable, which may carry a heavier DC current at the same voltage, a high frequency RF signal will severely attenuate itself in the smaller cable. You can see this loss on a scope by measuring it at the clamps, and then at the attachment point for the cable on the board. There is quite a bit of signal loss in the cables, regardless of size. Keep the cable run very short and the cable size heavy. Your pulser will be much more powerful, without pushing the unit to the burnout phase, if you use heavier leads. The easiest cure to this would be to take a burned out heavy duty (50amp+) battery charge and clip off 12" of the pos and neg leads and switch them to the pulser. Or take a set of battery jumper cables and cut off 12" of the cable with the clamps attached. Be sure to dismount the clamp from the leads, clean them scrupously and "Silver" solder them back on. Resin-based low percentage silver solder is availiable in any Radio Shack or electronic supply store. Elemental lead is a lousy conductor of electricity. Silver is about as good a conductor as it gets. Silver solder has about 5 percent silver and the rest being tin. It is the only sure way to solder sensitive and demanding electronic components. By silver soldering the leads to the clamps, you make sure that there are no choke points for the pulser's signal. It will erode and dissolve the sulfate crystals much faster and probably make the unit live longer.

BTW: I used many cable strands of "Litz" wire, bound togather in heat shrink, to make up about a 10AWG gauge cable and attached it to HD battery charger clamps. Litz wire is made of of extremely fine laquered copper wires and are braided togather in such a manner as to force the RF signal to use the whole wire's diameter and not just the skin. It's ungodly expensive and used for internal AM radio reception antennas, etc, where faint extremely high frequency signals can be carried without excessive loss. I managed to pick up a mile reel of 20/42 gauge Litz, off of Ebay, for a rock bottom price. I just kept clipping off 12" lengths until I had a big enough bundle. The laquer burns off at soldering temps. The bundle of Litz, transmits my pulser's signal spike with minimal loss.

And watch out when you connect your leads to a battery. Reverse polarity WILL instantly smoke your pulser, no exceptions. There are ways to build in polarity protection, but they drastically cut down on performance. These custom built units are race cars, not Pintos; They are not idiot proof...Treat them with the respect they demand and deserve or watch them smoke.

Guys,

For those based in the UK/ Europe I offer an alternative to the sites mentioned below by Don. These devices are very much based on the same original Alistair Couper design. They do work but are not a magic cure for all battery maladies. Check out http://www.courtiestown.co.uk

and

I don't have a web page, but you can find some info here:

http://www.flex.com/~kalepa/desulf.htm

http://www.homepower.com/files/desulfator.pdf

http://p198.ezboard.com/bleadacidbatterydesulfation

These are just a few of the sites out there. Just type in "desulfation" or "desulfator", and tons of sites will come up. I was overwhelmed by the new additions when I surfed it on the net this evening.

This is a relatively new science; New plans, kits and assembled units are coming on the net rapidly. Just do as much research as possible before investing...caveat emptor. Desulfation is no longer witchcraft, but it is far from accepted and what you may end up with, since it is a new enterprise, may be the real thing, or just window dressing. It's the wild west out there for now, but desulfator/pulsers are being recognized as a valuable tool....You can make a safe bet that the battery manufacturers are crapping in their britches, hoping this won't catch on, but the genie is out of the bottle now...Soon, even the most entrenched and unenlightened battery owning troglydite will have to recognize that desulfation isn't some fairy tale. I, for one, will be glad that less dead batteries are lying around in landfills or backyards, or wasting imported oil to recycle them."