Well you can look at it this way. How can ESD damage or destroy a battery? ESD can and will destroy a battery. You walk across a room and reach to pick up a battery, as you do so your body develops and builds up a static charge. How much charge? Heck it could depend on what you had for breakfast that day, how dry your skin might be and a dozen other variables. Really matters not.
Using your DeWalt 18 volt batteries as an example. DeWaly 18 volt battery packs are NiCad battery packs and they are called a battery pack because they are a pack of individual batteries. The battery pack happens to be 18 volts but each individual cell within that pack is around 1.2 volts. So that 18 volt pack consist of 15 individual 1.2 volt NiCad cells in series. Each cell having its own construction. Each cell having a negative electrode and positive electrode with a separator and electrolyte between them. So what happens if a charge far exceeding the dielectric constant of that separator punches a tiny pin hole in the separator? That cell is now destroyed and useless. The same can hold true for many of the individual cells in the pack. That is how a large electrostatic discharge through a battery can and does destroy a battery. The same way ESD can destroy other small micro-circuits.
With the evolution of batteries over the years different chemical compositions have been used in their construction. All batteries require different charging methods and designs. You do not for example charge a LiPo battery in the same manner you charge a NiCad battery. Battery chargers also use a collection of micro electronics to determine proper charge rates and voltages. Those same micro-electronics are just as unacceptable to ESD as a battery. With a large enough ESD charge they become damaged.
Anyway, so what does static guard actually do? So how does this stuff work?
Static electricity is an event that occurs when electrons from different materials come in contact with one another and cause an imbalance in positive and negative charges. When air is humid, the water molecules in the air help electrons transfer away from you and prevent a buildup of static electricity. The dimethyl ditallow ammonium chloride in Static Guard attracts water in the air, neutralizing the charge.
That is all it does. There is no magic bullet to it. Hell, you can make your own tossing a little Downey fabric softener in a gallon of water in a jug and spraying your carpets. When it won't work? When there is little to no moisture in the ambient air to suck up. Then it tends not to work as well based solely on how it works.
As to converting a reloading station into a ESD workstation? Yeah, you can do that. Keep in mind a few things. Using an ESD wrist strap does not ground the user anymore than an ESD workstation mat grounds the bench surface. Both provide a path to ground but through a very high resistance. A typical ESD wrist strap includes a 1 Meg Ohm resistor in the ground path or as much as 10 Meg Ohm depending on the application and the same is true of conductive mat materials.
Based on what has been covered your house wiring is fine. Your issue seems to be static. In my opinion you can try a spray and that failing (which I doubt) try a simple humidifier as I suggested earlier.
Ron
