Lead-Acid battery converted to Lead-Alum

Originally Posted by NobleMetalWorks

Before I explain what the plating is, lets first break down what Alum actually is instead of using it's industrial name. Alum = Hydrated Potassium Aluminum Sulfate or it's formula would be KAl(SO4)2·12H2O

John Bedini said to use straight aluminium sulphate and distilled water; Al2(SO4)3 + 12H2O.

As I understand, it is not possible to obtain aluminium from the electrolysis of an aqueous solution of a salt; aluminium itself in this configuration is not soluable in water, and the water simply electrolyses in preference to aluminium sulphate, so the aluminum does not precipitate out;, So is it electro-plating onto one of the electrodes (Lead/Lead oxide)? Which one does it plate onto, the lead cathode (Reduction)?



I am interested in this myself because i have been researching solid state electrolytes for batteries, and thought that this conversion would be simple and cost effective, but now it does not sound so great. I originally came across this idea reading on T.T.Brown's work on petrovoltaics; I wanted to make a crystal power cell! It seemed a good idea as I was researching the topic, but nobody working on it could explain what exactly was going on. I myself have made one such "lead-alum" battery from a 6v 2aH for testing to verify if this was in fact some kind of internet myth, now it seems it very well may be. Well the battery works, but as you said, the surge current that was once in the battery basically went away. Of course, there is no free energy here!

I do want to point out that this experiment does work with any 2 pieces of conductor with an electrode potential difference commuting through the proposed electrolyte, whether the electrolyte is liquid or solid. Wheather or not this is a good idea is another thing entirely.
Cheers!

Originally Posted by djbuggybee

John Bedini said to use straight aluminium sulphate and distilled water; Al2(SO4)3 + 12H2O.

As I understand it, aluminium itself in this configureation is not soluable in water, and the water simply electrolysies in preference to alumium sulphate, so the aluminum sulphate does not precipitate out;, So is it electro-plating onto one of the lead electrodes (Lead/Lead oxide)? Which one does it plate onto, the cathode (Reduction)?

Aluminum Sulfate is a salt, soluble in water, matter of fact it's made by mixing Aluminum Hydroxide with Water and Sulfuric Acid.

Aluminum Sulfate dissolves in the water the solution will contain positive aluminum ions, and negative sulphate ions. Now remember you also have hydroxide, which is really Lye. So once electricity is applied and the circuit is completed, the aluminum oxidizes and small amounts will plate out on the lead cathodes. We are not talking about large amounts, and we are not talking about precipitating aluminum, we are talking about plating small amounts of aluminum oxide on lead cathodes.

Now all it takes is to break the circuit, and the aluminum oxide easily comes off, most will just fall off and if not any jostling will help it fall off. As Aluminum is removed from the electrolyte the sulphate ion is liberated and converts back into sulfuric acid. Applying the electrical current over and over and stopping between will eventually remove most of the Aluminum and liberate most of the sulphate ions.

Battery acid is really just weak sulfuric acid, nothing more. So all you are doing is liberating the sulphate ions, creating sulfuric acid in the process.

But you are right in that no Aluminum in metal form is being plated out, that would take an entirely different process, using a molten electrolyte process.

It's far easier just to drive down to your local auto parts store and purchase new battery acid (sulfuric acid) instead of attempting to use this process to make a weaker, polluted version of sulfuric acid.

When I see "Aluminum Sulphate" I see it as it's component parts, aluminum, sulfuric acid, sodium hydroxide, etc. This makes it easier to understand how it can be broke down again into it's component parts. I know I can get sulfuric acid again, and I know sulfuric acid is used as an electrolyte for batter acid in lead/acid batteries, from that point it's not difficult to understand why these "converted" batteries work. What I have a difficult time understanding instead is how in the world so many amateur chemists get sucked into believing that somehow, a better battery is made by so called "converting" acid/lead to alum/lead. That makes no sense to me. I can understand someone with no background in chemistry at all, but not anyone with a chemistry background.

Scott