Sorry Bunkie, it is not. It is a disease of the battery whether in your motor home, travel trailer, car or truck that occurs when you put the battery to bed hungry.
A battery whether it is an Abosorbed Glass Mat, sealed maintenance free or a flooded type, does not make electricity, it converts with a chemical reaction to cause the flow of electrons, electricity. All batteries are made of two dissimilar materials dunked in an acid of some sorts called an electrolyte. The conventional auto battery that we all know and tolerate, uses plates made of lead, PB, and lead peroxide, PBO2, that are dissimilar metals. They are separated from touching each other by separator plates that are insulators. Not heat insulators but electrical insulators to stop the flow of electricity from plate to plate. The insulators also known as separators are pourus so that the electrolyte will flow back and forth.
The acid in the common car battery is a sulfuric acid solution that has a specific gravity reading of 1.275 when the battery is fully charged. The chemical symbol is H2SO4 or two parts of hydrogen, one part of sulfur and 4 parts of oxygen. This is important as the compound will change as the state of the charge in the battery changes.
When this cell is attached to a load, like a light bulb, the chemical reaction starts and electron flows out lighting the bulb. As the reaction take place transferring sulfur to each plate and oxygen to the lead plate. So as the battery approaches the dead zone the plates become similar, PBSO2, or lead peroxide plates with a coating of sulfur. The electrolyte now has become more or less H2O, which has a specific gravity of 1.000.
The problem is that the sulfur released from the electrolyte that now coats the plates has a tendency to form a skim coat over the plates that will harden if left on the plates. When it hardens two things happen: First it forms a barrier over the plate that blocks the flow of the liquid electrolyte to act on the plates. Second, the sulfur will not flow back to the liquid to re activate the electrolyte. The film does not form evenly and there are holes that still leave some of the plate surface that can be acted on. This action means that the battery will still function but at a reduced level. It is the surface area of the plates that results in how much load the battery can create. Reduce the surface area and we have a battery that will produce less amp hours of useable energy.
Most of the time re charging the battery will drive the sulfur back into solution and there will be no residual effect of the discharge cycle. And if the film of sulfur is left for a period of time nothing will drive the sulfur back into solution short of a little guy with a hammer and chisel climbing down into the cell.
The accepted test for sulfation is a two part test. The first is to take the open cell voltmeter test. That is with the voltmeter connected across the battery terminals and read the voltage. If the voltage is near 12.7 then we load test the battery. That is to apply a heavy load to the battery, usually three times the amp hour capacity that is listed on the case or one half the Cold Cranking Amps listed on the case. Apply the load for 10 to 15 seconds watching the voltmeter. If the voltage falls below 9.6 volts the battery has failed this part of the test and the three minute charge test is required.
When testing an automotive battery use a fast charger set at about a 45 amp charge rate. Again the voltmeter is the tip off as to the condition of the battery. If the voltage rises quickly and reaches 15 volts before the three minutes is up the battery has failed the test, probably due to sulfation. It has charged too quickly indicating a reduction in plate surface. The battery is no longer serviceable.
Sulfation is not some mysterious thing and is straight forward and can be tested. In the old day, when I was teaching Automotive Electricity at Sun Electric, we used carbon pile rheostats to apply the heavy load, but today there are computer based testers that using a computer model can and do test on a battery using very little current draw (load) and use the voltage time and amperage reading to model a pattern and give readings.
The trick to preventing battery sulfation is to not let a battery remain uncharged for a period of time. We used to say that a dead battery used to start sulfation after about 72 hours if inactivity and a low state of charge.
This is a general primer on batteries and sulfation And the numbers and formulas are close for academic explanations but a little off for engineering standards. But, who among us is going to build his own battery, just understand a little better the principles so that when the guy in the shop says, “your battery is sulfated and you need a new one”, it won’t sound like all Greek (no offense to the Greeks intended). This is also from the lecture at the beginning of the study of batteries when I was activly teaching. The finer points were deverloped after the student mastered the basic concept, so please accept it as it was ment.