Building a big Lead Acid Battery

[Jehu]

[Amr]

I dont know the effect of the acid on the fiberglass, and I'm not sure that the silicon ‎usually used for sealing the sides of aquariums would resist the acid, you may need to test ‎it first, I know it can stand for a big pressure but I'm not sure how it will react with acids.‎

I use fridge food keeping plastic boxes for my projects and for draining battery acids, ‎they work fine for that, they hold big weights and the tops can be easily removed and ‎most have their tops anti-leaking when closed. ‎

I never built a battery before so my input is only for the container

[Jehu]

Yeah, resisting the acid is my main concern. Next would be the ability for it to hold the weight of the plates and acid. My uncle had the idea of using glass fish aquariums but I'm not sure I'd like to have 35% acid in something so fragile. Another thought I had was using wheelie bins. they are movable and are pretty strong but I'm sure I'd run into some troubble trying to buy 260 Liters of H2SO4 if I was going to make 1 cell.

Thanks for replying too. Not much activity here atm.

But considering that the plates would be over a foot wide about 1 meter long and about an inch thick, it would plobably take about a week to charge but maybe hold a charge for 6 months. Just guessing though, have no idea how long it would really be.

[Amr]

If it is not going to be moved from one place to another, build a brick or maybe a concrete container and paint it internally with epoxy that is acid resistance. Fish tank may work if you make sure silicon will not be damaged by acid. I have a salt water aquarium that is 80 X 60 X 40 cm, but to move it from one place to another, it was placed since the beginning in a steel cage with enough enforcement from below and a plywood layer in between.
But if I were in your place, imho, I think I would start up by testing on a smaller scale, 1 m long plates is really huge, it will be very difficult to move it from the manufacturing place to where it will be placed without breaking it under its own weight, dont forget that lead is an easy to bend and hence, break material.
and why use plates with thickness of 1 inch? isnt the external surface area that works? so 1 inch or one cm will not make a big difference, that is why battery manufacturers stake several layers of thin plates, the more surface area due to more plates, the more the amps you can store.
But it seems a good thing to try, I wish you all luck.

[Jehu]

Not from my understanding. A large surface area will only affect current draw, not curent capacity. That's why a car battery has lots of plates and a spongy surface. It needs to supply alot of amps very quickly. Having really thick plates should let it hold a charge for ages. Ok, it might not supply the hundreds of amps in a few seconds that a car battery can but atleast I could leave some big lights on without the battery being dead after a few hours.

What I'm also thinking is that due to the big size of them, even if they sulfate up I could always give the cells a good shake to knock off all the sulfates. Every now and again, clean out the crud from the bottom of the cells to recover the lead later for when I need a new plate.

Ok, I probably won't go with such a massive cell straight off the bat. I'll be testing with something smaller, probably about a foot square after initial tests. The big bin idea was for later on down the track.

I'm not sure if the massive plates would break or not as lead is rather soft so it would more likely bend rather than break.

[Jehu]

I also forgot to mention that when I was messing around, melting one of the old plates down with my propane torch (why arn't I using hydroxy?) I noticed that there was a yellow something forming on top of the metal. I'm wondering if this might be some lead sulfate decomposing into lead and elemental sulfur? Might be an idea to try to collect the fumes incase it's sulfur di/trioxide.

[Amr]

Maybe when you start building the big one you would consider making a drain hole at the ‎bottom, this way you can drain, filter and then put back your electrolyte after removing ‎anything that settled on the bottom.‎

As for the yellow material, do you mean the paste that they coat the plates with?‎

I hope you would be careful enough not to inhale the fumes while melting lead as they ‎could be toxic.‎

Best of luck

[Jehu]

no, the plates had nothing yellow on thembefore I started melting them. They were a dark drey colour which then turns white to start then melts back into Lead. The yellow stuff stays on top of the old plates.

Don't worry, I was upwind of the fumes. Though I probably should be wearing my respirator anyway.

[mael]

This is something I'd like to get into.

When I read the title I thought of 'submarine' batts. And on the few lucky occasions I've managed to 'hit' a useful site about sub batteries, I've been encouraged to learn the people who work with them say they last a very, very long time.

I read about these battery-engineers actually reversing the polarity of the battery at some stage of its service life.

On another site I was reading about non-movable batteries which were periodically dismantled and during this dismantling, steel girders were placed on top of the lead plates to discharge them, and how these girders glowed red-hot.

I'd really like to get stacks and stacks of old car batteries 'n such, then get the lead out, refine it, and make dirty-great slabs for lead plates.

... However I couldn't do this with neighbours living so close - but then again, I don't really like them much... .

[Jehu]

[Veggibenz]

[Jehu]