Alum-Lead Battery Conversion
How to convert a Lead Acid Battery into an Alkaline Battery

... My friend claimed that you could take a weak lead acid battery, one that was still able to be charged but whose lifecycle was nearly finished and convert it to an alkaline battery by dumping out the battery fluid and replacing it with a mix of water and alum. Alum is sold in the super market spice section for making homemade pickles, it makes them crisp. It is sooooooooo cheap. And soooooooo safe, you can eat this stuff, okay? I don't recommend eating it because of the aluminum connection to Alzheimer's disease.

It is sodium aluminum silicate, chemically speaking. Also goes by sodium aluminosilicate, aluminium sodium silicate; sodium silicoaluminate; silicic acid, etc. For accuracy use the proper catalog numbers. CAS # 1344-00-9, GB 12493-90(02.002); INS 554; GRAS (GRAS means Generally Recognized As Safe) FDA 182.2727, (1994) If you want more complete chemical info, everything possible to know about this substance, you can download it here:


I experimented with old batteries and had two successes and two failures. The successes were total successes and the failures total failures. I used 4oz of alum to 1/2gal of water. You just replace the fluid, recharge the battery and off you go. The successful batteries seemed to be more powerful than the original, however I have no data. The best one was destroyed in a vehicle fire. It has been over 10 years since I did those experiments and I am getting ready to try again.

The advantages of the alum battery are many :

The battery fluid is non corrosive -
the battery gas is not explosive -
the battery can be discharged more deeply -
the battery can be charged faster -
the battery will last longer -
there is not corrosion of the terminals -
it is extremely cheap -
more power in cold weather

I will be trying this experiment with some better measuring tools. I want to go to a battery shop and try this on numerous old junk batteries. My feeling is at this point, if the battery is too dead to take any charge at all, it is too far gone to recover with this method.

This process has never been commercialized that I know of except by one company in China. From what I can read, I think that their battery is pretty much the same as this homemade solution, but all worked out scientifically. It is extremely simple. I'd love to have some assistance from more knowledgeable folks on how and why it works to be able to perfect it.

When you realize how cheap this is to do, you'll really be doing some head scratching. You can have a renewed battery for the price of a few bottles of alum.

Another related bit of information is this. There was a company set up in China called Guineng who was manufacturing and selling a new type of battery. They indicated on their web site that it was a silicate salt battery. I'm pretty convinced it was of this type I am experimenting with. Well, they had a good site with lots of info. But there has been no success on my part in contacting them in any way. I've tried like the dickens to get ahold of this company but have never had an email response, cannot get through by phone, just impossible so far. They were reported to be selling their battery to E-Max scooters in Germany. The bikes are being sold down under and the first reports on performance are coming in. But here it is, take it and see what you can do with it.

I am going to try to be working out the correct ratio of alum to water myself in the future for my new used battery bank...

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Sep 3, 2012

Alum lead battery

February 2, 2008
Posted by: arkansascajun

I GOOFED GUYS! i just learned i made a TYPO. it's 10 oz. alum per 100 oz. distilled water or 1 oz. per 10 oz. i am SORRY!
also i used USP grade ALUM.

A few observations

CAUTION: the people likely to replicate this experiment know this:
1. Use personal protection and safety precautions when removing the battery electrolyte.
2. Due to its lead content it is industrial waste (poison) and must not be poured down the drain or into nature.
3. The water used for the alum electrolyte needs to be distilled or fully demineralized water. Tap water ruins the electrolyte (or does it in this case rovide helpful trace elements?)

TRUE - the battery fluid is non corrosive
FALSE - the battery gas is not explosive
REASON: what gasses out of the battery when charging is not the alum but as usual the elements water is made of, oxygen and hydrogen, an explosive combination.

LIKELY UNTRUE: The claim that the silicon battery is less environmentally harmful is only true if it is NOT using lead, so it is a technology different from the topic of this posting.

LIKELY TRUE: when my family car's battery gets old (in 5-7 years), I'll try to rescue it with the described alum electrolyt

January 28, 2007
Posted by: Sepp

Jonathan comments --


This is a great discovery, but the idea of "dumping" the contents of the old battery really creeped me out. It is very poisonous, dangerous toxic waste. That liter or so of liquid in a lead-acid battery is sulfuric acid that can burn your skin and blind you if splashed, with a huge amount of dissolved lead, so it must be taken to a hazardous waste company for disposal.

February 6, 2007 09:51 PM |
Posted by: Sepp




April 8, 2007
Posted by: Tim B

I used to rebuild automotive batteries for a living. Back then, you just heated up the tar seal and pulled the cells. I can tell you that most battery failures are due to vibration, where the plate or a cell connection breaks.

Life expectancy is mostly affected by high current draws that actually flex the plates. This leads to loosening of the powdered lead on the plates. The powder builds up in the bottom of the battery and eventually reaches the level of the bottom of the plates. At that point, the cell plates short and it's finished.

After plastic batteries were introduced, we couldn't take them apart anymore. So we simply invert the battery and drained the acid into a Poly plastic container. The acid won't eat poly or styrofoam. Use poly gloves, not latex. A lot of the crud comes out with the acid.

Fill the cells with water, agitate and invert into another plastic container. A small trash can works well. Repeat this process until the battery rinses clean.

Wait a few days. The heavy lead products in the acid and the rinse water will settle to the bottom fairly quickly. The container with rinse water you can neutralize with baking soda. An electrolytic process can probably remove the remaining dissolved lead products, but most of it settles. Pour off the clear liquid until the crud is left at the bottom. Leave it in a plastic bucket until it dries. Or, if you do this regularly, save this rinse water for other batteries.

Filter the acid and reuse in the battery. You will need to top off the cells with more. Pour the leftover crud into the drying bucket.

About 50% of batteries will get a useful life again.

As far as replacing the sulfuric acid with Alum, I would be concerned about the aluminum precipitating out of solution and causing shorts. But the biggest problem with lead/acid batteries is the lead, not the acid. I think I'll try it though.

September 25, 2007

since i didn't want to waste a good battery i started this experiment by using my oldest junk was literally covered in the weeds, had been open for years and was half empty. i topped it off with distilled water and charged it up. but when i tested it @100amps it showed as three cells dead. i looked inside it and saw that three of the cells were caked up in that white crystaline SULPHATION that shorts out the cells. i knew there was no chance that it would work in that condition so i resolved to clean it up first. i did this by making a gallon of solution of distilled water with as much baking soda as it would dissolve mixed into it. i dumped out the battery and filled it with this solution. WARNING: wear EYE protection and old clothes and shoes. even a small drop of battery acid will eat a hole in them. WARNING: fill slowly because the chemical reaction is violent and will boil over and shoot out if done too fast.

i noticed that when full it continued to bubble about like it does when charging. i let it set overnight until the was no sign of chemical reaction. upon inspection i was pleased to find the battery plates AS CLEAN AS NEW. no sign of the white crystaline SULPHATION.

i dumped this solution out and replaced it with distilled water. i reasoned that this would absorb any residual baking soda. i let it stand overnight. i dumped it out and filled with the ALUM electrolyte solution of 1oz. ALUM per 10oz.'s distilled water. and hooked up the charger. at first it didn't want to take any charge. after i BUMPED it a few times by hitting the quick charge switch on the charger ( i figured it needed to be RE-POLARIZED) it started to take a charge. but only around 5 amps. over a few hours this increased to 15amps. when the charger showed the battery was full i tested it with a 100 AMP LOAD TESTER type meter. it showed as marginal weak. i knew this battery had previously shown three cells dead. it still showed three cells dead but also showed the other three as GOOD.

this indicated to me that the principle was valid so i decided to repeat the experiment with a good battery. i followed the same procedure wityh a DIEHARD group 65 700cca battery that was several years old but still tested as good after one test @100 amps but marginal weak after two tests. after filling with the alkaline i tested it and it immediately checked as OK but on the low side. i charged it 4 hours @15 tested as high as a new battery. even after four tests @100 amps it still showed as good.

CONCLUSION: usually when somethings too good to be true it ain't. but this is contrary. THIS WORKS!

September 25, 2007
Posted by: arkansascajun

one more point i left out. don't just blindly believe what someone says about sulphuric acid bieng a pollutant. it's actually used to TREAT WASTEWATER ( google it ) and except for killing a few ameobas or worms when dumped on the earth it simply returns to where it came from. it's SULPHUR.

January 26, 2008 08:08 PM | Posted by: Raymond Lohengrin

I tried the Alum on three batteries. I followed these steps:
1) Removed and stored the acid.
2)Cleaned the battery with baking soda/water solution.
3) Washed with water three times.
4) Washed with destiled water.
5) Filled with Alum 10z to 10oz water.

Charged the battery to 100% but battery lost the charge rapidly as before. It seems that is the battery is good the Alum will work just fine. If the battery is bad, the Alum is not going to help to bring it to life.
One of the batteries I filled back with acid instead and the behavior was the same as with the Alum.

I read that you can open the battery and clean it. I did this carefully but the plates will break easily. I believe it will be very hard to pull the complete plate group as one without damage to them and for me is not worth the effort!


PS I may try the alum on a better battery. I did tried also on sealed batteries by removing the top plate. I found the have caps just like regular batteries but they are covered with a plastic plate that can be removed with easy. I had the same result as with the deep cycle batteries. Fast charge but rapid lost of voltage.

February 1, 2008
Posted by: tshell

Regarding the alum conversion:

1. The ratio I have always used is 4oz of dry alum powder to 64 oz of water. I have recently converted a battery with 50g alum to 1liter of water. That is very close to the same ratio.

Some have posted using very high ratio's. They may work, I don't know. The water will only absorb a certian amount of alum and then reach saturation. Saturation is 68 to 79mg/l at 20*C, ph - 9.

It is not necessary to use so much alum. Save your money.

Regarding appropriate candidates for conversion:

If the battery will not take or hold a weak charge, then it may not be able to convert. The conversion process uses the sulfation of the plates as a catalyst in the chemical reation. So it is not necessary to do any washing or rinsing with baking soda solution. The sulfation of the plates begins reversing when you add the alum solution and it will end up being removed over time.

Choosing a very old and malfunctioning battery for the conversion may not yield a useful battery after conversion.

There is enough evidence from my work and that of others posting that the concept is valid and works well on appropriate candidates for conversion.

What remains is to more scientifically calculate the ratio of alum to water for the project.

I am convinced from what I am seeing that the Greensaver battery can be essentially homemade by the alum conversion technique.

By the way, I have started a new Yahoo Tech Group to discuss battery conversions.

It is called BatteryConversions.

You can access it at Yahoo Groups:

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