Homemade lead acid batteries



  • Deveak_KaizenDeveak_Kaizen Registered Users Posts: 31 ✭✭
    Its kind of expensive in the US if you buy "battery acid" from auto stores, its pretty cheap if you buy in bulk from chemical suppliers.
    Some sell it by the ton for under 300 bucks. So pretty close to 2 bucks a gallon. Most likely your paying so much because of hazard shipping and environmental laws. While its messy, with some preparation you could filter and concentrate battery acid from car batteries.
  • mcgivormcgivor Solar Expert Posts: 3,564 ✭✭✭✭✭✭
    edited March 2018 #33
    @BjornM said, I know what you mean. Almost every single component for a DIY battery is hard to find in Sweden. Didn't use to be like that when I was a kid, but now everything is considered dangerous for people or the environment. I have no good source for sulfuric acid yet. Ironically it is one of the cheapest chemical substances in the world. When I lived in Thailand, you could buy it for $2 per gallon.

    The current price in Thailand is 10 Bhat per 620 ml beer bottle ~6 per US gallon, so still around  $2 at current exchange rates, probably much cheaper if purchased in bulk 
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  • clockmanfranclockmanfran Registered Users Posts: 67 ✭✭✭
    edited March 2018 #34

    Battery Acid for our particular batteries would be Sulphuirc Acid, 1 to 15 ratio to De-ionised water/distilled water.

    I use a 80% sulphuric acid and can be readily obtained in  500ml bottles in Europe with out to many issues.   So 500ml would make about 7.5 litres, (about 1.5 us gallons). .....  See pic of bottle in my Fume cabinet, with the label disappearing from just the fumes alone.

    I think that this homemade battery topic may be raising false hopes regards getting batteries cheap, and now its getting technical and in the Dangerous Acid discussion area. Perhaps another more technical Forum may be better appointed.   Depends on the Mods here?

    Safety protection at all times.

    PLEASE PLEASE remember, NEVER NEVER NEVER ADD water to the NEAT Sulphuric ACID solution.

    ADD the Sulphiric Acid to the water very carefully and slowly, and let it disperse within the water. Even so when adding correctly in just one go, in one spot on the water, the solution gets very hot very quick, and spits and spatters.

    Don't mess with neat sulphuric acid it does permanent damage to our fleshy bodies.

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  • BjornMBjornM Registered Users Posts: 8 ✭✭
    edited March 2018 #35
    Since the Plante method of forming lead sponge at the electrodes is so time consuming, how about make the electrodes really thin so the process can be faster?

    Lead has low structural integrity, and would easily fall apart when very thin. Instead, lead coated copper foil could be used. This foil could be sandwiched with very thin polypropylene felt, and rolled up into a cylindrical shape. Each layer around 3 mm thick.

    From a research article:

    "The conditions for copper corrosion were investigated with regard to its use as the negative grid material in high performance lead‐acid batteries with gelled electrolyte. The experiments on copper sheets show that only under very extreme conditions, when there is a thin electrolyte film on the surface and no lead coating over a distance of more than about 3 mm, copper dissolution can occur. In this case, substantial potential shifts in the thin electrolyte film, resulting in a much more positive potential at that part of the electrode, were measured. With a properly lead‐coated copper grid there will be virtually no copper corrosion even under starved electrolyte conditions."


    EDIT: Rewritten for clarity.
    Off grid in a small cottage in western Sweden.
  • Deveak_KaizenDeveak_Kaizen Registered Users Posts: 31 ✭✭
    Neato! So you can use copper to strengthen the grid or plate? You can order fumed silica online. A rubber cork could be used as a over pressure valve. Not sure if a real 1-2 psi plastic one way valve could be had. The copper and pure lead would certainly mean a low resistance battery.  You could probably do a plante plate with an inner copper grid for strength. Eventually it will be exposed but by that time the plate would be pretty compromised anyways.
  • Deveak_KaizenDeveak_Kaizen Registered Users Posts: 31 ✭✭
    GOLD MINE! A huge thread in italian, google translated by a guy who worked with primordial batteries. Lots of info on its construction.
    It took him 4000 hours to reach his target goal. Technically it could go higher but that would compromise cycle life. Straight charge and discharge. He said the reverse method made it gain capacity faster but shed a lot of material and had to be done at low current. This seems like the perfect battery for solar. It grows and grows. You could half form it and just let the day to day use do it for you. His original design (although i don't think he kept it this way) was without separators and had them far apart. I would not do this. Not sure if spacing adds up enough resistance vs separators. So much to read!

  • petertearaipetertearai Solar Expert Posts: 446 ✭✭✭✭
    question ... not related to making your own battery ... but what do people use sulphuric acid for , seeing as you can buy it in large volumes.
    Do people in Thailand have another use for it ? 
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  • mike95490mike95490 Solar Expert Posts: 9,051 ✭✭✭✭✭
    question ... not related to making your own battery ... but what do people use sulphuric acid for , seeing as you can buy it in large volumes.
    Do people in Thailand have another use for it ? 
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  • BB.BB. Super Moderators, Administrators Posts: 31,091 admin
    Just a generic link to the large number of uses of sulfuric acid:


    How many of those have an "in home" use... Probably not many (my plumber used "professional only" sulfuric acid to clear a clogged drain--It worked great for that--Lots of bubbling and heat).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • simmtronsimmtron Solar Expert Posts: 87 ✭✭✭
    mcgivor said:
    Yes lead is toxic, but with all relevant precautions, the hazards can be reduced to near zero, the closest I've personally come to recycling batteries is replacing plates with manufactured plates, during my apprenticeship, before the molded case battery technology, am I dating myself?  
    yes you are dating yourself, haha
  • GrrGrr Registered Users Posts: 1

    @BjornM I would recommend making salt water batteries. Salt water batteries have much lower energy density compared to other energy storage solutions, but are dirt cheap to produce and are made of completely non-toxic materials - in fact you can safely eat the materials used in their construction and not be harmed. In addition to those benefits, they are very safe and resilient. You can discharge them very deeply daily, and the materials are not flammable and are safe to touch.

    Here is some information on salt water batteries that I gathered together from duckduckgo.com searches:

    Please reply with how construction goes, I am very interested in this endeavor myself.

    @wayneworkman I just found your post. Very interesting but not much details to work with. I guess I need to start with general battery principles and details, and work from there. Regards
  • soloronesolorone Solar Expert Posts: 255 ✭✭✭
    Interesting thread. I know nothing about this, but it brings to mind the 1910/1930s the 32 Volt Edison batteries in jars.  Sears sold 32 V.  gear. The elders of then related to me that at times the lead was removed and new lead replaced. I guess   nothing is  new. 

  • BB.BB. Super Moderators, Administrators Posts: 31,091 admin
    Here is a fun/interesting link that details Lead Acid batteries used in Farm Lighting systems circa 1922
     or so:


    And the whole archive:


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    tabbycat said:
    Lead is toxic.
      lead is at least 90+ % recyclable ...  lithium ion on the other hand is less than 65%, and everything left is so virulently toxic that it makes lead and mercury look like a joke.  Pull your head out of al gores backside.

    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
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