Alum battery conversion.

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DavidA:
Well, the alum arrived so it's time to make a start.

Now, as my transatlantic colleagues seem fixated of quaint measures like Bushels, cords, and particularly fluid ounces I needed to do a bit of conversion.

First, in the video he uses 8 Fluid Once to 1 gallon of water. Now, 1 US gallon = 3.785 Litre.
A session with my wife's kitchen ware shows 8 fluid ounce of Alum to be close to 250 Gram.

My battery holds just under 2 Litre of electrolyte.

So, I only need 130 Gram (52 %) of Alum in 2 Litre of water to do the job. Anyone who sees a flaw in this logic please feel free to jump in; preferably tonight.

My baking soda (Sodium Bicarbonate) came from Aldi in 200 Gram tubs.

I drained of the acid into a container for future experimentation, mixed up a tub of bicarb' in a two litre milk container
and filled up the battery; much bubbling ensued.
When the bubbling had died down I drained it all out and repeated the operation. Still bubbling, but not as vigorously.
This time when the bubbling stopped I placed a bit of electrolyte from the battery into a beaker and added a few drops of universal indicator. Bright red. So, still acid.

I have left the bicarb' solution in the battery for the night. Will check again tomorrow.
I also checked the Alum to be sure that it is also acid.

Oh yes, 9.8 volts across the battery with the bicarb' solution in it.

More follows.

Dave.

DavidA:
Update,

Last night I drained off the bicarb'. rinsed it out with fresh water and filled up with the Alum solution.

The battery voltage (no load) was 9.8 Volt.

Connected up the charger and found 0.1 Amp flowing. Same as before.

Three hours later it had increased to 0,4 Amp. Not much, but better than before where it had refused to go past 0.1 Amp.

Today at 12:30 the current was at 0.5 Amp. With the charger disconnected there was 12.7 Volt across the terminals.

So it looks as if something is happening.

The plan is to leave it a couple more hours, then use my big charger to increase the current to around 5 Amp (if possible).

The a series of discharge/recharge cycles.

What fun we have.

Dave

awemawson:
I'm intrigued what the alum / lead paste chemistry is - particularly having seen that video where a 'recovered' battery started a largish and very cold engine.

I once successfully revived a set of traction batteries on a 'works truck' (small milk float) that had stood uncharged for years. I bought one of the high voltage pulse revivers and did each 12v battery in turn. From discharge tests it got back to well over 90% of it's original capacity, and while I still used it regularly it held charge well. It was a bit tired when I sold it as again it had sat unused for a year. Only through the reviver away yesterday - I'd blown it up by reverse connections and opening it up it had some custom components that weren't available.

DavidA:
Andrew,

Yes, this puzzled me also. In fact it sees to surprise the guy who made the videos.

I'll have to ask the chemists at my old works and see what they have to say on it.

I can understand the bicarb' helping to desulphate the cells, which would be beneficial. but can't see why you don't just refill with Sulfuric acid at the correct SG (1.250) afterwards.

I have another battery in a similar state. Maybe I'll do the same first stage on that one but refill with Sulfuric acid instead of Aluminum sulphate.

All interesting stuff.

Did you watch the whole series, four parts?

I was particularly impressed by the way the battery seems to hold it's charge and still start the truck over a three month period. And you can tell by the weather changes that he isn't trying to fool anyone.

Dave.

vtsteam:
David, I did a lot of youtube viewing re. the alum electolyte after you started the thread. The person who seems to have done the most experimentation and has the most interesting and informative videos with this and many other unconventional cells is Frank Bedini (Energenx):

http://www.youtube.com/user/Energenx/videos

Lots of video viewing interest there.

He's very firm on using distilled water. and also I believe doesn't use baking soda to neutralize, but just distilled water rinses. He does "form" plates through a time and current regimen on new cells. He mentions 10% alum solution in one video, but in another (initerview) video states one cup/gallon as the electrolyte proportion which is 6.25% by volume (US measure)

Also I've seen a few other videos by others, but find them kind of frustrating, as they never seem to have the patience to do a steady 1C discharge and calculate the capacity (vs. the mfr lead/acid capacity) of the lead/alum battery. They always jump around for the video and increase the discharge rate after 15 minutes -- I guess they get bored. One guy who uses "ammonium alum" from a deodorant (????) does use a steady 150 ma discharge for a couple cycles, on new cells (but without forming) and I make out a severely reduced capacity (maybe a third?) He also seems to have created a supersaturated electrolyte -- crystals of alum form in his mixing vessel, and presumably in his cells....

Anyway, all very interesting, and looking forward to your results!

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