Not totally snake oil but a lot has been left out.
Add all the things you need to do and the cost ends up the same as buying a new battery.
Using Epsoms salts will result in magnesium being deposited on the plates.
To remove this you need to refill the fully chrged battery with sulphuric acid at about 1/2 charged strength and let the battery sit for a while.
next you need to complex the magnesium out of the electrolyte solution by tipping it out and treating with a 20% EDTA or DMG solution.
Filter this 3 or 4 times to remove all of the precipitates and set aside the solution.
Now vigeriously wash out the battery at least 3 times with deionised water to remove all sludge from the bottom which shorts out the cells
now return the filtered acid to the battery and add just enough water to just cover the plates and too a deep cycle recharge.
Tip out the acid and adjust the strength to that of fully charged acid and return it to the battery which if all went well might just be at 1/2 to 2/3 new capacity.
You now have to discard a lot of toxic material.
At no time must you allow the plates to fully dry out as you will get PbO and PbO2 forming on the plates and this will require a totally different regeime to clean off.
Add to that the bonding material in the paste breaks down once it dries out allowing great chunks of paste to fall to the bottom of the battery where they form a dead short.
Inox market a battery treatment which has a pile of complex ionic salts that will act as a secondary electrolyte solution allowing a dead flat battery to be recharged, if it is in a recoverable state, ie left flat for a moderately long time but not allowed to dry out.
A cell that is dead is generally dead because of a build up on the bottom of the batery and will respond to a simple washing with some carefull agitation.
We did this at the scrap, yard for years.
However with motorcycle batteries it is generally due to the plates fracturing from vibrations & shock loads.
Replacing the acid with some 1/2 strength acid was generally the next step for thought to be good, flat batteries.
Fork lift batteries got a partial DMG or EDTA treatment to see if there was a sufficient response to warrant going the full hog.
Deep cycle batteries can be revived in some cases with high voltaged pulsed charging which causes gassing at the plates, The generation of and collapse of these bubbles, blast off a little of the paste thus revealing a nice fresh surface to the electrolyte with the downside of the paste layer being thinner = less capacity and the possibility of the detached oxidised paste shorting out the plates. Starting ( car ) batteries generally do not respond as well to this as their paste is quite thin to start with, in fact as thin as mechanically possible and still have better than 95% of the production make it past the end of warrantee period.
This post like most of the crap reposted on the web by people with absolutely no background knowledge is about 5% fact and 95% fiction.
The key to look out for is any hint of a conspiracy motive ( they don't want you to know this…etc )
Battery retailers send their old batteries to a recycling factory where they are cut up & recycled.
Every part of a wet lead acid battery is economic to recycle and is in fact the only part of your car that is economic to recycle.
The conspiracy come in where you get charged a "disposal fee" for something that they sell for a nice cash profit.
With the advent of dirty Chineese manufacturing, the world lead price is rising faster than gold on a % basis and several old uneconomic lead plants are being recomissioned.
the scrap value of the plastic cases i going up at about 20% pa and has been doing so for a long time such that it was for a while more expensive than the lead it contains.
The big cost with lead acid batteries, is however transportation handleing & regulatory expenses since the mere sight of a piece of lead will now cause instant blindness, eye & throat cancer and if you are living in California, sterility , lung cancer, leukaemia, prostate cancer, diabeties, obseness and insanity for the following 20 generations of your prodigy
