I was wondering if it would be possible to build big lead acid batteries using large plastic storage tubs like the kind that Wal-Mart has? I have a lot of lead plates and some sulfuric acid laying around. What would the acid to water ratio be? Any ideas would be appreciated.

-- Keith (halfc@fidnet.com), October 03, 2001

Answers

Hmm, acid in plastic? Dont think so.

-- Gary (gws@redbird.net), October 03, 2001.

Those big plastic containers really arent strong enough, I use them to store green wood untill I can use it so it doesn't split. But the containers do split. That is not something you want to happen when you are using them to store acid in. The answer is no, don't, and at least if you do move down stream from me.

-- David (bluewaterfarm@mindspring.com), October 03, 2001.

Well said. My sentiments exactly. There are some things that you can cobble together without a great deal of risk. A large lead acid battery in a sudden catastrophic failure (container failure, hydrogen explosion, fire or acid spray) is not one of those things. If you just can't help but experiment, please do it on a small scale. Isolate your tests from sources of ignition and protect yourself from acid injury. Been there, done that. Tee shirt fell apart when I washed it.

-- Frank Hill (fhill@absolute-net.com), October 03, 2001.

Hi Keith. I just know you are going to be a careful sort of guy so let's just skip to the practicalities?

I think the trick is to get as big a surface area on the lead as possible and also to get the positive and negative plates in close proximity without actually touching.

Now sulphuric acid is quite a bit heavier than water (at least I think it is) and filling a big tub probably is quite hazardous.

Seeing as you have the lead and the acid how about thinking of a 'pile', i.e. a stack of plates separated by some sort of acid impregnated separator? Maybe polypropolene carpet tiles?

Just my idle musing!

-- john hill (john@cnd.co.nz), October 04, 2001.

How about big plastic ice chest? Lots stronger. Whats this about acid and plastic? Have you not noticed what your car batt is made out of?

-- DG (Spedstar5558@yahoo.com), October 05, 2001.

the chemistry is simply lead and sulfur, I believe. so it will work. all of the above cautions about the dangers are understated. Hydrogen gas is extremely explosive when mixed with the right amount of air. Sulfuric acid will eat anything organic. Commercial batteries have a significant amount of antimony in the lead, I don't know why, could be because it's cheaper to manufacture that way but could be because it changes the strength of the plates so that they don't collapse and short out. your will have to isolate the wire connection going to the load from the internal environment of the battery or you WILL have electrolysis that could provide the spark to ignite the potential bomb. Have fun.

-- kirby johnson (kirbyj@deskmedia.com), October 05, 2001.

Ummm...I'd just like to know how one happens to have sulfuric acid "laying around"??

-- Tracy Rimmer (trimmer31@hotmail.com), October 08, 2001.

Tracy, sulfuric acid is used to treat alkaline garden soils, which we have plenty of here in the West. It is a by product from the copper mining industry and can be gotten cheaply.

-- Joe (CactusJoe001@AOL.com), October 08, 2001.

Thanks Joe. Yet again, I'm caught with my "stupid" showing!

-- Tracy Rimmer (trimmer31@hotmail.com), October 09, 2001.

If you ever seen a car battery blow-up you may think twice about what your trying to do . Chemical reaction to produce electricy is a science. As an electrician myself I would not even consider it. I have seen large commercial fork lift batteries open big holes in a factory when they blow. Even short circuits are very dagerous..Please buy them don't build them...

-- Brian Major (steelcave@hotmail.com), November 26, 2001.

Uh, I think you guys may have been "taken", again.........

-- rc (rjc@hotmail.com), November 26, 2001.

Yes you could do it, but it would make a lousy battery. One of the plates in a normal Lead-Acid battery is really porous (the negative I think) a flat plate won't have enough surface area.

FWIW the antimony used in batteries is there to strengthen the lead. The plates are typically really thin and pure lead is soft so it would sag without something (the antimony, or fiberglass mats in some batteries) to suport it.

Also the acid in batteries is pretty weak, I've gotten it on my skin numerous times with nothing more than a slight rash ( I don't even bother washing it off normally).

The hydrogen problem, isn't. Provided you have enough ventalation it won't build up to the point where it's hazardous.

-- Pete (peter_v@hotmail.com), December 11, 2001.

There is no point in doing so. Most lead acid batteries thrown out can be recovered with a chemical treatment or by building a desulfating pulse generator. Plans for a homemade pulse generator are at,

http://www.shaka.com/~kalepa/desulf.htm

Be sure to read the original article in a link near the top.

-- Don Denhardt (desulfator@yahoo.com), January 23, 2002.

i hear a lemon and 2 wires work perty good,ahah

-- c.r (c_ross@hotmail.com), March 03, 2002.