We have uncovered evidence desulfation by means of pulse charging - as advertised - seems to have a hitherto undocumented, totally different effect.
We liked the concept of sulfation pulse treatment and believed we understood it, but were disappointed after searching patent databases around the globe. We found 53 patents strung out like pearls on a necklace in time, successively describing each and every previous invention as flawed, then each in turn going on to propose a radically different pulsing technique. Electrical, as well as magnetic and mechanical - from intense pulses lasting mere microseconds - some lasting tens to hundreds of milliseconds - to square wave on-off at second to multiple minute intervals. Pulsing at various states of charge, pulsing at a wide variety of rates, steady pulsing, patterned pulsing. Resonant and non-resonant pulsing. Jolting the batteries at an optimal structural resonant frequency or at a "sulfur crystal resonance of 3.26 MHz". Plenty of theories and anecdotes - nothing concrete.
It is clear that shortly after lead-acid battery pulse technology became an item of commerce, it began attracting large numbers of enthusiasts - like bees in search of the proverbial honey pot - looking for a share of the action. Individuals who go into business making battery pulse devices are, of course, entitled to take out new patents, provided these are directed to protect specific details that have not been identified and described by anyone else.
The degree of diversity among all these patents provides a convenient and surprisingly accurate way of determining the true level of understanding of the technology. The databases show the pulse technology patent subject matter is extraordinarily widely scattered - the bees are still flying around searching for the honey pot - confirming there is definitely something not right with this technology.
Pulsing began gaining popularity around the same time major battery manufacturers introduced extra-low-maintenance and maintenance-free automobile batteries, manufactured with lead-calcium grids. Lead-calcium alloy grids were originally developed by Haring and Thomas in 1935 and have proved extremely difficult to implement. These batteries have a propensity to fail due to something known in the trade as "passivation" or "open circuit". It has also been described by battery technologists as the "antimony-free effect".
Lead-calcium alloy develops an ultra-thin, very poorly conducting tetragonal lead oxide, (alpha-PbO), layer on the surfaces of the positive plate grids over time, leaving the positive active material isolated from the supporting grid structure. Battery manufacturers use tin to control this oxide layer. Addition of more than 1.5% tin to the alloy reduces the passivation effect - critically, at 0.6%, tin provides a significant worsening of the effect, (Nam Bui et al, THE TIN EFFECT IN LEAD-CALCIUM ALLOYS, Universite Henri Poincare, France, 1997). Tin is expensive, so as little as possible is used, with unpredictable results. There are more than 100 patents describing tin, as well as other metals, alloyed with, or plated onto positive grids - suggesting this is a highly problematic technology. Silver is also beneficial but is excruciatingly expensive. The original lead-antimony alloy, introduced 130 years ago by Sellon, has always been absolutely 100% trouble free in this regard.
Then why change? Lead-calcium technology batteries use one-eighth the amount of water of lead-antimony - are made maintenance-free by hydrogen/oxygen recombination technology - but generally last only half as long. Evidently maintenance-free is perceived as important, reasonable battery life is not. These Pinocchios like to say the batteries of today are better than ever before! Welcome to the throw-away society!
The problem presents with the battery suddenly refusing to crank the engine. Then, when it is put on charge, its voltage rises almost immediately, as if it is already fully charged. All the external symptoms, (including low SG in flooded batteries), are identical to sulfation, yet this is definitely not sulfation. The application of strong, high frequency pulses, acting substantially in the same direction as the battery charging current, is breaking down the ultra-thin oxide insulating layer and in that way has been restoring battery ampere-hour capacity to a serviceable level. Pulse equipment manufacturers: An industry asleep at the wheel.