Refurbing battery?
 

I've read about using epsom salt/distilled water in the right proportions to replace the electrolyte and then trickle charging it several times. Has anyone had any experience with this or is it just bull?

never heard of this but I have brought back a battery by replacing the electrolyte.

The electrolyte in a car battery is not salts...sulfuric acid at about 30% concentration in distilled water. Adding anything but water is risky, as water is what is lost from it (evaporated). The main problem with batteries is the sulfate buildup on the battery grids. there are some chargers which apparently can bring them around (maybe a small improvement) but it is hit or miss. good luck.

What chemical will neutralize and/or remove sulfate build up?

That would be the key - neutralize and remove the sulfates from the lead grids (or between plates, depending on the type of battery in consideration), and stop the shorting.

If you "dump" a battery, the contents in your container will be sulfuric acid, water (maybe), and lead sludge.

Often, cleaning the lead sludge from a battery and adding new electrolyte and PURE demineralized (deionized) water is sufficient to "renew" a L/A battery, although not to original capacity. (Remember, you just removed some lead... it's not going to be 100% anymore).

Salts, red wines, and some other things (Coca-Cola, I think?) can temporarily "boost" or "quick-charge" a battery due to chemical reaction; However, most batteries you'll come across today are sealed or "maintenance free" type, and accessing the cells is difficult/impossible without damaging the casing.

EDTA is the best one I've found, JC Whitney used to sell a good mix that was easier to add to the battery than pure stuff. (which must be dissolved in water first)

Remember though EDTA will only work if the battery is sulphated, if its shorted or damaged it won't do a thing.

Epsom salt again can allow a sulphated battery to accept charge but it also has negative side effects like faster self discharge and faster positive plate wear, I guess it could be worth a try but there are better alternatives that cost about the same. (like edta)

And remember the epsom salt must be dissolved in water before it can do anything.

Cheers
Ryan

It looks like the sulfation of the lead plates makes the sulfuric acid more basic so adding epsom salt, water, and energy via heat/charging provides more sulfuric acid by stripping the Mg from the epsom salt.

Memory
 

I seem to remember a "miracle" (lol) product that would revive a dead battery "instantly" (minutes) if you dropped a tablet of it (about the size of a .177 cal BB) in each cell of the battery.

I always figured it was epsom or something similar. Maybe it was just chloride tablets? LOL.

I've used EDTA with good luck, when my parents got an electric push lawn mower the battery was junk so we put EDTA in it and charged it a few times then used it for the rest of the summer, I've also had really good luck with battery desulphater chargers, on the same mower, the best tho is the little battery desulphater box that connects right to the lead acid battery as it apparently does a pulsed charge discharge on the battery, to keep the plates active and clean, I have a device like this on my electric car battery pack and my parents have one on their batteries for the PV panels.
I've also been told that you need to bring a lead acid battery up to full charge and hold it there for 12 hours or so, so basically leaving a trickle charger or smart charger on the battery over night, I've done this with my Civic's battery (4 years old) when I thought it was on it's last leg after leaving my lights on a few times -20F weather and the battery is still strong.

Not exactly, what you say does gradually happen but it is much more complex than that.

Sulphation is non-conductive as is depleted acid (water) epsom salts conduct very well and pass through and into the sulphation allowing the plates to charge (which does cause heat which helps to break up some sulphation), they give up their Sulphur to the battery plate and break away sulphur in the sulphation (depending on if you are charging or discharging)

The magnesium also interacts with "rusted" lead.

Lots of things happen when you add epsom salts and being able to charge is one side effect.

Worth a try as the stuff usually does work but again at a cost. EDTA is better and an EDTA wash is better yet.

Good Luck
Ryan