Reviving a lead acid battery

Probably not. The lead plates develop a sulfate coating that diminishes the batteries effectiveness. Replenishing the acid doesn't help.

It's a little more complicated than that. It can be done but not by merely adding more acid.

There are two things normally associated with dead car batteries. 1.) is the acid has gone out of solution and bound itself with the lead plates to form lead sulfate. You no longer have the ionic polar differences to manifest as current. You need to drive the acid out of the plates back into the water. That's what recharging normally does, but doesn't always work because 2.) some of the lead has settled to the bottom, shorting out the cells, and 3.) the water is dead, inert, neutral; has lost it's electrical liveliness.

I've managed to recharge a car battery dead for months. Here's what you need to do:

a) Open the caps, invert and set the battery over an empty 5 gallon bucket, let all the water and free lead drain out. The water will be very weak and won't burn your hands. (Note if yours is a sealed battery, may as well toss it as this method won't work.)

b) filter out the free lead thru a strainer/coffee filter. Rinse out the cells really good so all the free lead is out and gone.

c) fashion a vessel from any expendable metallic cylindrical container. Set an insulator at the bottom of said container. Set a smaller metal cylinder on the insulator, central to the larger container. Don't allow them to short or touch. The inner cylinder and larger container should be about the same height.

d) Add your older battery water to the vessel. Begin charging by hooking leads to the metal cylinders. I use 60Hz power mains through a step-down transformer, full-wave rectified. I use a light-dimmer on the AC side to regulate current, but also to add electrical spikes that work much better for recharging than just a sine wave.

e) I found that adding a little colloidal silver to the water, helps greatly.

Run this setup for 20 - 30 minutes, then add the water back to your battery. Toss the free lead you strained out, it's useless now.

Begin charging your battery using the same circuit used to charge the water. Let it charge for a week. You'll get a snap off the jumper electrodes but possibly no steady current. You now need to do steps a) thru d) again, several times over the battery charging cycle. Every time you do, you'll find the water getting more strongly acidic; when it really bites your hands to the point of needing gloves, you've arrived, your battery is restored. It may sound like a pain, but it really works !)

Thank you Thrival. I am impressed with your knowlege.

What happened is that my 6 month old (barely used) 12 V deep cycle lead acid battery lay inside a plastic battery box that inadvertently filled up with water and I did not discover it for 2 months when we returned to the property where the battery is stored.

I emptied the box of water (several gallons) and the battery still works and charges but it seems to discharge with use rapidly. I thought maybe the acid was diluted within the flooded box and that adding fresh acid would invigorate the battery.

Any help appreciated J

Are you sure the plates have not buckled or split and are shorting out somewhere?

I am not sure at all. Is ther a way to check for this?

I am sure there must be a way by measuring the resistance or something but as batteries are not my strongest point, you better ask some petrol head here on the forum.

If they are buckled due to excess water absorbtion or whatever, did it freeze?, than i think it is broken beyond possible repair.

Also if the water shorted the battery out for long enough time, it could also damage the plates irrepairably.

Maybe somebody else with more exact knowledge can comment better on this as I am not entirely sure.

Several points to make.

First, just by sitting, what happens is any free lead in the acid-water, does tend to
settle to the bottom and short the cells. It may not be a dead short, but almost,
causing the battery to go or "behave like deadness" faster. The floating lead
contributes to this.

Also it seems not all cells sulfate from acid, or short from settling lead at the same
rate.

You might actually be a little low on acid. Mix up a batch of acid-water, about 15%
acid with distilled water, add to the battery and let it sit. Short the terminals and
let it go dead-dead. You've just sulfated the cells good if they weren't already.

Drain/empty the electrolyte and save it; strain out all the free lead through a double-
layer coffee filter as suggested. Rinse the battery out several times with clean tap
water. I mean put the caps on, invert and shake it good. You are removing the lead
settled at the bottom. Several flushes will show there's still plenty of lead in there.
Discard the rinse water responsibly. {8P

Now you can re-add your original, strained electrolyte (or fresh distilled) and begin
charging. It's going to take a while, probably a week. Don't exceed 15V max or it will
only drive lead into your electrolyte without recharging. That's why periodically
dumping the electrolyte and charging it in a secondary charger (concentric stainless
pipes are best), can speed up the process. Water does store an imposed charge, so
by charging the acid-water external to the battery and adding it back, you energize
the electrolyte and avoid overcharging the battery. Yes it's a pain but some of us are
just damn cheap and expect miracles(!) You may not ressurect the dead, but batteries
are a start! (LOL)

"It's ALIIIIIIVE!" --Dr. Frankenstein

Crikey! I am impressed! Thats the sort of thing they should be doing as a science project at schools, although in the real world, when I can go and buy a new battery for about £25 ($50), I'll not go to the bother!

V. Good way, specially in war or Marshall law times.

Anybody could state USA requirements for acid disposal?

Anybody could state USA requirements for acid disposal?

I think the left-over lead is more of an issue. The acid can be diluted down to the point of being irrelevant, poured on the azalea's which love acid soil. No lead-loving plants that I know of . A good place for the lead would be places that balance tires, I always see a bucket there with old wheel weights.

Tom

Further to, if you're looking for a fast way to restore a dead battery that won't take a charge, try this:

Apply your charger to your battery in series with the battery! In other words you aren't just further discharging the battery, you are removing lead from the plates, i.e. electroplating it away, into solution! Don't do this too long, you are only wanting to remove a very thin coating of lead from the plates, any oxides or sulfate.

Dump the lead-acid water and rinse out the battery thoroughly several times, vigorously shaking it to remove all settled lead.

Visit a local chemical supply house and pick up a gal. of H2SO4 (sulfuric acid), cost $20.00 as of today's date, and a gal. of distilled water (about a buck) at your grocer. Mix these up in a bucket and measure with a battery-hydrometer to obtain 4 of the 5 balls floating (state of full charge) and using a plastic funnel, carefully add the acid- water solution to your battery.

Presto, "brand new" battery! I did this today, restoring two batteries.

Note, you will use about 1 quart of acid to 3 quarts of water, but the hydrometer will indicate exactly. Also remember to add acid to water, NOT water to acid! The solution will heat up, could splash, so wear goggles. And don't spill any on your clothes unless they're filming another Mad-Max sequel and need extras!