Simple question, difficult response.
I’ll make an effort to be as brief as I can in my response.
Lead acid batteries prematurely fail in over 70% of cases due to sulphate crystal build up, which has been known about since the creation of the lead acid battery. However, all batteries eventually lose their capacity, and nothing can stop that from happening.
Battery manufacturers have made great strides in the last 30 years or so to combat sulfate build up and improve the life span of their batteries by introducing changes to the construction of the battery plates, and under ideal conditions, proper maintenance and correct charging, sulfation should not be a problem.
However, since the world is not perfect, sulphate buildup continues to be the main reason for battery failure.
It has been discovered that a controlled overcharge of the battery will damage the crystals, but if used correctly, it will keep the batteries clean and extend their useful life. This method is not recommended to be used on sealed lead acid batteries (also known as AGM or VRLA batteries)
A pulse generator, also known as a desulfator, is a straightforward device that produces high voltage pulses that are sent to batteries. It was invented about 20 years ago. Since it wasn’t regulated, this had the same practical effect as a controlled overcharge but eventually caused damage to the battery plates. This reversed the beneficial result. Many of the low-cost devices on the market today are constructed using these designs, and the circuit board diagrams for these kinds of devices are freely available online. Long-term harm from a short-term fix.
At the same time, other options were being considered. Experiments revealed that, if the right frequency could be achieved, sending a frequency pulse to the battery could dissolve the sulphate buildup. However, different frequencies were needed for various sizes of crystal that accumulated on the plates. Therefore, the single frequency devices were and are still hit or miss, some functional and others useless.
A device that could operate with various frequencies, voltages, and battery sizes was required. Building a device of this kind used to be very expensive (costing over $1,000) and large (being the size of an old-style video player). No businesses were willing to develop them because there was no way to assure the end-user that sulfation was the cause of their battery’s issues.
Small, reasonably priced products that can clean the plates of batteries of various capacities and voltages are now possible thanks to dramatic reductions in component size and cost.
In order to recover old batteries or prevent new batteries from accumulating sulfate, a small number of manufacturers now make products that can clean the plates of old batteries and stop the buildup. In essence, this process extends the life of any battery that is not charged or maintained properly while recovering a lot of old batteries. They can only recover batteries with no internal damage, shorted cells, or AGM batteries that have dried out, according to responsible manufacturers, and this is all that they can do.
You should look for suppliers who give clear instructions on how to test for faults within the battery or who offer a telephone or email service to help with any issues you may have using a desulfator or with your particular battery setup because it is impossible for suppliers to determine the condition or faults of the batteries customers intend to use the device on.
In conclusion, modern multifrequency desulfators can significantly extend the life of your lead acid batteries and recover a sizable portion of sulphated batteries that would otherwise be scrapped. They are not a panacea that will fix all defective batteries, however; rather, they can recover a sizable percentage of sulphated batteries that would otherwise be scrapped. This would significantly lower your replacement battery costs, which are significant for applications like solar storage batteries, ride-on golf carts, fork trucks, large boats, and motor homes.