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Convert Lead Acid battery to Alkaline — Parallax Forums

Convert Lead Acid battery to Alkaline

prof_brainoprof_braino Posts: 4,313
edited 2014-07-05 14:16 in General Discussion
I have an old deep cycle lead-acid battery from a Basement Watchdog sump-pump system. The battery died after a couple years, and it just sat in the basement corner for a couple more years. There was zero volts when I tested it last, no reading on the volt meter at all.

I heard we can convert a dead lead-acid battery to an Alkaline battery.

I dumped the electrolyte and mixed it with baking soda to netralize it. It did not bubble, it did not even fiz. The liquid was very grey. I rinsed it with distilled water intil I got tired of lifting it, the water still comes out grey, but the very fine particles settle faily quickly. I haven't figured out what to do with all the Nasty lead sulfide water, but got pretty clear after I let it settle and poured it through a coffee filter. Now I have a bucket of clear but questionable liguid, and a baggie full of dirty coffee filters to get rid of, but thats a separate issue.

I mixed up a solution of distilled water and Alum, with Alum 10% by weight.

Upon filling, the battery read 4.4 volts. By the time I got the charger set up, it had risen to 4.5 volts.

The folks on You Tube for Bendini Battery/Alum Battery say a "still working" battery (that can hold at leat some charge) should be charged at about 12 to 16 volts (?) for 15 to 20 hours. Mine was totally flat 0 volts, so I'm making some adjustments for my set up.

I connected a big ol' regulated power supply. At 12 volts, the Amp meter ready 0.03 Amps. I gradually increased the voltage to 21 volts, till the amp meter read 0.31 volts. The amp meter reading has been rising about 0.01 A per minute. Now the amp meter reads as 0.85 amps after less than an hour.

The Bendini Battery video on YouTube says they want to chargw at around 12 volts and 1.6 amps for 15 to 20 hours.

I think I should charge at the higher voltage until the current comes up to around 1.6 amps, then reduce the voltage to maintain 1.6 amp charge rate. Maybe I'll wait till it comes up to 1.0 amps, then start reducing the voltage, till the volts are down to 16.

Has anybody else tried this? Any suggestions?
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Comments

  • prof_brainoprof_braino Posts: 4,313
    edited 2014-06-29 15:45
    After one hour on the charger at 21 volts, the current was up to 1.12 amps. I disconnected everything aqnd checked the battery with the voltmeter. The battery read 11.6 volts. This is what the YouTube folks said they got.

    I think I'll try running one 12 volt 10 watt LED with a constant current modlue (from ebay). Then I'll turn the charger back on, and try to reducing the voltage to keep below 1.6 amps, if it ever gets up that high. I probably won't charge for the whole ten hour tonght.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-06-29 21:01
    I've never heard of the process you're using, but I have restored "dead" lead-acid batteries using EDTA. It's a chelating agent that dissolves the sulfate deposits on the battery plates. My experience with it has been positive on the whole.

    -Phil
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-06-29 23:57
    Very odd change over. You do realize that the old electrolyte is chock full of dissolved lead and should never ever be poured down the drain? It is just about the easiest way to pollute the environment with lead.

    My gut feeling is that DIY battery fixes are very environmentally hostile.

    Kaohsiung finally closed down tiny shops that would salvage lead from car batteries and other sources. These guys would just empty all the electrolyte in to the gutter outside the shop. From there, it was going directly into the nearby bay and fisheries.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-06-30 11:33
    After three hours, the charge rate was 17 volts, and 1.6 amps. (The instructions said about 12 volts and 1.6 amps for 15 hours for a "good" battery). When I took it off the charger, it read 11.8 volts, just as predicted in the instructions.

    It sat overnight off the charger, and after 11 hours, the voltage read 7.5 volts. I'll try to charge it again, but I don't want to leave it unattended for more than about 20 minutes. So probably three hours each night this week.

    I plan to try it again on a battery that can still hold some charge, with electrolyte that is still acid, when one becomes available.

    These are supposed to tolerate deep discharge, overcharge and other abuse with less consequence, and last longer. The trade of is reduced capacity. So far its been interesting, but kind of a mess.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-06-30 12:25
    If sounds as if the lead has precipitated out and formed a sludge. If so, you could let it dry out on some paper in the sun, and dispose of it properly. The rest of the water/solution may or may not be environmentally safe. Ideally, just let it evaporate and then deal with the residue. But without adding heat, that could take a very long time. The lead is in solution in the ionic form when involved with an acid or a base. Without something organic happening, I suspect the neutral solution drops the lead out. I'd have to check around to be sure.

    It might just be easier to ask the Chemistry Department of a local university what to do with it.

    In university I was one of the top three in my General Chemistry class. We three used to ace all the exams and finish the 2 hour exams in about 20 to 25 minutes. But when asked to major in Chem, I declined as it seemed an excellent way to poison myself and others. In nearly all my science courses I got 100% on all the mid-terms and didn't have to take the finals.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2014-06-30 12:30
    In university I was one of the top three in my General Chemistry class. We three used to ace all the exams and finish the 2 hour exams in about 20 to 25 minutes. But when asked to major in Chem, I declined as it seemed an excellent way to poison myself and others. In nearly all my science courses I got 100% on all the mid-terms and didn't have to take the finals.

    Yeah - and look at you now.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-06-30 12:37
    It's embarrassing isn't it? Rock n' roll and the 1960s got a hold of me. I could have been a real engineer if I had gone to Oregon State instead of that hippy University of Oregon.

    I'll be celebrating my 20th year anniversary in Taiwan next month. Back then I had a log log slide ruler and a case that would hang on your belt -- real leather. Maybe I even had a pocket protector too.
  • Dave HeinDave Hein Posts: 6,347
    edited 2014-06-30 13:26
    Has anybody else tried this?
    No.
    Any suggestions?
    Get rid of the battery before something bad happens.

    Seriously, why are you messing around with this stuff when you could be writing code instead? Take the battery to your nearest Walmart, pay any disposal fees they ask for, and leave before they start asking too many questions.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-06-30 14:12
    There are places that will pay you for old lead-acid batteries. A couple blocks from where I live is a convenience store that pays $4.00 per battery. It's a real scam, when you figure that the current spot price for lead is almost a dollar a pound. Now think how much those batteries weigh; it's almost all lead. And it's pure lead, too -- not corrupted with antimony or other base impurities.

    -Phil
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-06-30 14:21
    There are places that will pay you for old lead-acid batteries. A couple blocks from where I live is a convenience store that pays $4.00 per battery.

    But then you don't have to worry about disposing of the lead in the acid.

    This DIY lead battery stuff is disturbing to me. As Loopy said (about pouring the acid from the battery down the drain.) "It is just about the easiest way to pollute the environment with lead."

    I did major in chemistry. There's a lot of stuff that should not go down the drain or into the gutter. Lead salts are one of these.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-06-30 15:52
    According to this article, the electrolyte never contains any dissolved lead. It ranges between dilute sulfuric acid and water.

    -Phil
  • GenetixGenetix Posts: 1,754
    edited 2014-06-30 16:10
    Here in California you have to pay a core charge when you buy a new battery unless you give the store your old one. Lead is toxic so it's better that it's recycled than contaminating the environment.
  • GenetixGenetix Posts: 1,754
    edited 2014-06-30 16:12
    Dave Hein wrote: »

    Seriously, why are you messing around with this stuff when you could be writing code instead?

    rotflmao (Rolling on the floor laughing my a$$ off!)
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-06-30 21:34
    After another three hours of charging, its taking 1.6 amp at 16.5 volts. This is near what the instructions suggested, so it might be imporving. I'll check how far it drops overnight. I guess I can keep doing this until Saturdy, and if it doesn't work out I can drop off the battery and the sludge at the battery store
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-07-01 00:33
    It isn't the lead plates in the batteries that concern me so, but the electrolytes of all sorts ... not just lead batteries. The electrolytes had a dissolved mixture that includes the metals of the plates, but that isn't all.

    Nickel is claimed to be carcinogenic
    Cadmium is a notorious heavy metal
    Even Lithium ion cells have electrolytes made with fluorine that out gas in a failure.

    In a lead acid battery with H2SO4 for electrolyte, I guess the sludge from neutralizing would include Lead from the plates, Sulfur from the H2SO4, and if Sodium Bicarbonate was used to neutralize, you would have Sodium as well.

    At least we got rid of the Leaded gasoline and lead white in house paint. The biggest pollution factors are gone.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-07-01 06:58
    Thanks for all the input guys!

    Is any of youse an electro-chemist? PM me if you don't mind me picking you brains for a proper write-up.

    Phil's article suggest that the electrolyte is only water, given that the acid is gone. I'm saving the liquid, and filtering out the sludge, and reusing the liquid to rinse the battery, since its the correct volume. I'm saving the coffee filters with the sludge so it can all dry out. Maybe my next project will be figuring out how to separate metallic lead from the sludge, and make lead shot for the survivalist guy down the street. You never know which favors will come in handy...

    I think my risk of contamination of several milligrams of lead might be less of an issue than the 26 million tons of lead used in industrial battery production each year. Using a wire bush to clean the corrosion off the terminal cause more contamination than what I'm doing (if you don't include me cleaning the corrosion off the terminals with a wire brush).

    After letting the battery sit over night, the volt meter read 9.3 volts with morning. So it might actually be charging. I'll charge for another several hours tonight. I guess I should make a note when I have reach 15 hour total charge time, and again when I reach 20 hours.
  • Martin_HMartin_H Posts: 4,051
    edited 2014-07-01 07:18
    I agree with Loopy that chemistry is an excellent way to poison yourself if you're not careful. College level chemistry spooked me because of the warnings they gave us about certain chemicals. We did one lab with radioactive calcium that made me extremely nervous. The Periodic Table of Elements YouTube channel has a video of the chemistry professors discussing which chemicals they thought were the most dangerous. One of them had the initials VFD which referred to Very Fast Death factor.
  • Mark_TMark_T Posts: 1,981
    edited 2014-07-01 08:51
    Is lead stable in alkali? Lead is (kinetically) stable in sulfuric acid because a thin layer of PbSO4 forms on the metal
    surface protecting it from further attack (nitric acid and HCl both dissolve lead).
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-07-01 09:50
    According to this article, the electrolyte never contains any dissolved lead. It ranges between dilute sulfuric acid and water.

    -Phil

    Hmmmm......... very good point. It appears that the lead doesn't go into the ionic solution, but may go into suspension as the battery deteriorates and form a sludge on the bottom. In the nice tidy formulas, it is all Sulfuric Acid, H ions and OH ions.

    I guess I was just pondering that it was similar to Ferric Chloride that is used in etching printed circuit boards.

    ++++++++++++++
    I suppose the lead in the coffee filters could just be melted in a furnace and the sulphur would burn off. The sodium might alloy with the lead or burn off. Would it really matter if the lead wasn't pure and contaminated with sulfur and sodium? We not only left tons of lead bullets all over Iraq, there are a lot of uranium bullets as well. A wee bit of sulfur and sodium seems silly to worry about.

    I don't have any good chemical references here to sort these things out. Haven't looked at such since the 1970s.

    +++++++++++++
    I did work for awhile in a photography lab where we salvaged all the silver that went into solution in the developing process. There certainly was enough silver to get money back from doing so.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2014-07-01 17:49
    I could have been a real engineer ...

    As opposed to what other kind?
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-07-01 19:58
    As opposed to what other kind?

    Hey, give him a break. He's been working real hard lately to reach 10,000 posts.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-07-01 23:34
    @RDL2004
    P J is mentoring me in misanthropy. Please don't give him a hard time.

    The 10,000 post thing is rather awkward. Being a V.I.P. by the quantity of comments doesn't mean much of anything. There are others here that know far more than I do.

    I do have an E.I.T certification from the State of California, Department of Consumer Affairs, Board of Professional Engineers, Land Surveyors, and Geologist. But I don't consider that to represent being a 'real engineer'. I never acquired a PE in a specific discipline, though I was a home builder, designed homes as permitted by law, and worked a lot in projects involving civil and structural engineering.

    I'd have to say a 'real engineer' has the authority to sign off on a project and backs the design with his signature.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-07-02 15:49
    A real engineer drives a train. Aside from the funky hat and boots, I don't see much point. The boots are pretty cool though.

    Today, after letting the battery sit over night, the alum-lead battery reads 10.1 volts. It looks like its might be starting to take and hold a charge.

    I turned the charger back on at 1.6 amps, and its pushing 15.2 volts. I'll let it run for another 5 hours or so today. Immediately after the charger stops, the battery reads 11.8 volts, as predicted by the Bendini instructions. I think if it sits overnight and reads 11.8 volts in the morning, I might consider the battery charged. If it gets that far, I'll work on load testing. Although I only need it to run a prop and a few LEDs, maybe just leaving the LEDs lit for a couple days might be a sufficient test.

    If you do get the inclination to puzzle over recovering lead, please make suggestions on the easiest way and how dangerous it might be. The web says something about an oxygen free carbon monoxide atmosphere.
    There must have been a simple way in the musket and powder days. Could I maybe put a ceramic bowl in the middle of a charcoal fire and cook it out that way? Would there be any chance of gassing the wife's yap-dog? Let me say in advance that would be a tragic accident. Just how would I acomplish this? I mean recovering the lead.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-07-02 17:41
    I'd get an old stainless steel pan from your local thrift store (one with sloped sides is best) and put it on the coals -- outdoors, of course -- with the lead sludge inside. As the lead melts it will be very drossy. Try stirring in some beeswax as a reduction agent. Then skim off the remaining dross, let it harden, and take it to the hazardous waste disposal. As to the molten lead, let it harden in the pan, then pop it out. Then take the pan to the hazardous waste disposal, too.

    CAUTION: Always wear safety goggles when working with molten lead. An NEVER pour molten lead into anything that's wet. It will explode back into your face and eyes, causing severe burns and possible eye damage. Did I mention wearing goggles?

    -Phil
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2014-07-02 18:29
    The web says something about an oxygen free carbon monoxide atmosphere.

    Can't think how that could pose any problems.
    Start the car with the garage door down and then go recover your lead.
    Simple.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-07-02 20:09
    PJ Allen wrote: »
    Can't think how that could pose any problems.
    Start the car with the garage door down and then go recover your lead.
    Simple.

    Thanks for your input. I was thinking more along the lines of covering the grill once the charcoal was hot and the container with the lead sulfide was in it, but I imagine my rig is too leaky to maintain the proper atmosphere and still sustain fire.

    I think I'll try Phil's suggestion, its simpler. I'll keep your suggestion in mind in case gas prices come down.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-07-03 15:26
    Last night when I turn the charger off, the battery read 11.8 volts again. This morning, the battery had dropped down to 10.5 The afternoon, it read 8.5 volts.

    Now, this is different: When I turned the charger back on, it was pumping in 3.5 amps at 14.4 volts. Last night, 14.4 volts was only pushing 1.6 amps.

    I turned the charger down until to 1.6 amps, the voltage says is 12.4 volts.

    It seems the current is now steady falling, after a few minutes the current is reading 1.57 amps. So somethng appear to have changed today. I'm hoping it means the battery is finally charged, although I realise its more likely that it means the battery needs to be thrown away. I'll leave it on the charger again this evening since I can't get rid of it till Saturday anyway.
  • Dave HeinDave Hein Posts: 6,347
    edited 2014-07-03 17:13
    prof_braino, I'm sorry to inform you that the patient is dead. Please do the right thing and take it off of life support. I didn't know your battery personally, but I'm sure it had a good long life. However, it is time to let it go.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2014-07-03 17:49
    If you have little funeral for it in the backyard then please DO NOT mention it here.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-07-03 18:48
    I have to agree with youse. Except that its less dead than before I started the experiement.

    I connected a 10w LED, which is supposed to draw 1 amp, to one of those 12vac to 9VDC constant current modules (off ebay of course), and connected to the battery.

    It started off pretty bright, but the amp meter says its only drawing .75 amps, and dropping off fairly quickly. I just went back and checked and its down to .50 amps.

    Which is pretty good for a completely dead battery, I guess, but its not going to work for my emergency lighting unless I figure out a way to improve it.

    The instructions say the battery improves after a few charge - discharge cycles. I guess I'll let it run down tonight and try charging again tomorrow, and see if I can notice a difference.
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