We had several pulsers available for testing from four different manufacturers (one manufacturer provided six or seven different models, including pulser only and charger/pulser types, 12V and 24V).
The first interesting thing we found when we put them on a spectrum analyzer was that the pulses emitted by these devices were all different!
Very different. In timing, pulse width, amplitude, frequency, etc., etc.
Which, naturally, led to the question of how they could all work if they were all very different, esp. in frequency, one from the other.
A national testing lab of great repute did some testing on one of the models we tested, and found similarly that there was no discernable positive result. Sorry, I'm under an NDA (non-disclosure agreement) and can't tell you any more.
For a time, it appeared that new models were hitting the market every few weeks or so. Quite the fashion :-) And, the pulsers have attained a cult following, with dedicated affectionados confecting their own. Circuits are available on the Internet
, and these have been substantially modified by "cult" members.
I remember one fellow who built a "super pulser" which apparently wiped out his TV every time he turned it on :-)
Again, our tests weren't "scientific" in the real meaning of the term. We did take pains to lay out a testing protocol, to employ excellent equipment
, and to carry out the protocol as best we could over a lengthy period. At least in our tests we found no reason to believe that the models tested -- on the batteries available for testing (gels and flooded golf cart size batteries, well used) -- had any significant impact.
After many months of cycles involving pulsing/charging/discharging to 10.5v, then pulsing/charging/discharging again, the pulsers and pulser/chargers appeared to have little or no impact. However, a single equalization
cycle (15.5-16.5V overnite) did have a measurable positive
impact on the four flooded T-105s. After that, the pulsers seemed to provide no further improvement.
We can surmise that the equalization
impact came mainly from agitating the electrolyte and knocking some of the PbSO4 crystals off the plates, but then the corollary conclusion would be that the pulsers -- which had at that point been in use for six months or so -- failed to deal with the sulfation problem.
As you study this problem more closely, and as you read and explore the many factors involved in battery performance and testing, you realize that any definitive statement about the pulsers would have to follow from a large-scale, independent (probably government-funded), longitudinal study by a capable laboratory. So far, this hasn't happened to my knowledge. But, I'd be first to say that it should, if only to answer the deceptively simple question we were trying to answer, "do these things really work, or are they snake oil