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Author Topic: Alum electrolyte conversion experiments  (Read 9418 times)


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Alum electrolyte conversion experiments
« on: December 25, 2012, 07:13:12 PM »
First off, I'm new to the forum and would like to thank many of you for your youtube videos that brought me here. Many of you have been a real inspiration to me. Regardless of what you believe, I wish you all a happy season and a successful year of experimenting to come.  :D

I've been working to get myself off the grid as much as I can, but doing so does not seem to be cheap. Most power systems need a storage medium and deep cycle batteries are quite expensive. I recently took an old mower battery that would no longer charge and switched the electrolyte to alum. After washing the cells out and neutralizing them with baking soda until it would no longer bubble, I added 3/4 tsp of alum to each cell and topped them off with distilled water.

Three trickle charges later, it seems like I have a working battery. Not only can it power LED lighting and run a small inverter, but it can also produce enough power to start the mower like it was originally intended:

I'm now testing to see if the more alkaline electrolyte will enable the battery to withstand deeper discharges and more charge cycles than the acidic chemistry allows, drawing inspiration from the performance of the Edison cell. Here's the collection of my experiments with alum chemistry thus far:

Based on this bit of success with the system, I am going to try building my own cells and batteries to store energy and power my experiments.


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Re: Alum electrolyte conversion experiments
« Reply #1 on: December 27, 2012, 05:12:37 AM »
The lead acid battery is an amazing device.

The topic you've initiated should prove interesting
and certainly is worthy of exploration.

It would be a good test to obtain two lead acid
batteries which will no longer take a charge in
order to perform a comparative study.  Ideally
the batteries would be the same type and with
the same Ampere Hour Capacity rating.

One of the batteries could be rejuvenated by
means of pulse desulfation without any change
to its internals or its chemistry.

The second battery could be "converted" similar
to what you've done with your mower battery.

After both batteries have been rejuvenated to their
maximum restored capacity a series of tests would
be performed in order to evaluate their discharge
rates and capacities in order to note any differences.

Which of the Alums did you use for your experiment?


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Re: Alum electrolyte conversion experiments
« Reply #2 on: December 27, 2012, 03:13:41 PM »
My goal is to make comparative study between the two, but lack two identical batteries right now. I'll have to start with brand new batteries to do a real study on the matter. These lawn and garden batteries would be good test subjects, due to their low cost.

The one thing that I can study accurately right now is how well it will withstand deep discharge compared to the well known data on that with the starting type lead acid batteries.

My truck's battery is 8 years old and reluctant to start the beast on cold mornings, so I'll have another battery to power my experiments.

The alum used is the potassium type. If nothing else, this shows how we can rejuvenate a battery if we lack the proper equipment to do so with the acid electrolyte.

My mower battery is currently undergoing discharge cycle testing. I'm on the 4th cycle, and it seems to finish each charge with a slightly higher voltage than before when everything has leveled out. Perhaps the electrodes are still forming under the new electrolyte?


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Re: Alum electrolyte conversion experiments
« Reply #3 on: June 16, 2014, 03:28:22 AM »
BroMikey at the other forum has much to say about the
Alum (Ammonium Aluminum Sulfate) Converted Batteries.

He describes how two of his batteries (100AH) lost capacity
after abusive "normal" charging methods.  After conversion
he claims that the lost capacity has been restored and that
the capacity has even increased.

Observing an increasing capacity with lead-acid batteries is
a common phenomenon and it is actually by design.  At some
point in the life of the battery its capacity will begin to diminish,
usually due to accumulating sulfation, and it will drop below its
rated capacity.  To assure that the battery will have a long, useful
life each has built into it more than its rated capacity which will
begin to show up after the first several charge/discharge cycles.

I wish BroMikey had done a comparison with:

(1) A Lead-Acid Battery pulse charged, fully desulfated and load
tested periodically to establish capacity,


(2)  An Alum-Converted Battery, also pulse charged, fully desulfated
and load tested periodically to establish capacity.

Unless those kinds of comparisons are made it is very difficult to
know with certainty whether the Alum-Conversion has accomplished
anything more than what  Pulse-Desulfation is able to accomplish.

As other experimenters have pointed out, Aluminum Sulfate is acidic
as is Ammonium Aluminum Sulfate.  Potassium Alum and Sodium Alum
are less acidic and tend more towards neutral since Potassium and Sodium
are highly alkaline.