I'm sure you didn't mean to make light of the concept
of double-blind studies. That would be unfortunate.
You might also be interested to know that over an 18-month period three of us conducted a study of the effects of the little pulsers, including several examples of yours. About 10-12 in all from several manufacturers were tested. Ours wasn't a carefully delineated double-blind study, but we did make an honest attempt, using a written protocol based on known concepts and practices. We also used some of the best test instruments available, recorded our data, and tried to draw conclusions.
The main goal was to determine whether or not these things worked at all, or whether they are merely "snake oil". Over the course of the study we learned a lot, made some mistakes
, discussed our findings, and tried honestly to give these little devices a chance.
First significant finding was that the pulses ALL differed significantly, one from the other. In frequency, duration, amplitude, bandwidth, rise times, amperage, etc. That raised the obvious question: if they're all different, how can they be effective?
We surveyed the literature as well, and found a veritable cult following for these devices. Circuits all over the Internet
, home-built models, chat groups, low-powered, high-powered, etc., etc. One fellow claimed to have a very powerful home-built pulser which "tore up the TV" every time he used. it!!
Unfortunately, after a year and a half we were unable to discern any significant positive effect from the use of these devices that could not be attributable to other factors. A respected national scientific laboratory came to a similar conclusion. I regret that I am not at liberty to disclose the details of that study since it was privately commissioned.
I have a bunch of pulsers in my shop right now. And, before tossing some of the test batteries which have been charged but idle for a year or so, decided a few weeks ago to put a couple of the pulsers on two banks of golf-cart size gelled batteries, and measure any changes in capacity with a Midtronics MDX-650 tester. After several weeks of charging/pulsing there was no measurable benefit.
However, what we did find was that the equalization process
(15.5-17.0 volts for several hours) had much greater benefit on restoring battery capacity than did months and months of pulsing and exercising. Further, the pulsing and exercising AFTER the equalizing did nothing to restore additional capacity. This was true for flooded, AGM and, yes, even gelled batteries.
Bottom line is that it's very hard to say for sure that these pulsers really work, notwithstanding the voluminous anecdotal information supporting their "benefits".
Interesting that Jedi mentioned double-blind studies, because one of our conclusions was that the real truth cannot be found without large-scale, longitudinal, and expensive laboratory testing -- funded by some government
agency. This is because the variables are too many for even experienced and interested electronics
types -- like ourselves -- to fully and completely control for. Wish it weren't so...I'd love to have a little device which could so easily extend the life of my batteries significantly. But, alas, I don't think it now exists.