Lead acid battery

Forgive me if this is a dumb question. Why can't I dump the acid out of a dead battery. Rinse it out with distilled water and refill it with new acid? Would that not make a new battery? Is it not the contaminated eletrolite that causes a battery to go dead? I know batteries can be rebuilt so what else would they do?
An old gentleman in my area used to rebuild them and sell them with a lifetime warranty so I know it can be done. I just don't know what all he did.
Dave.

I did that before and it didn't help at all. Looking it up the battery failure is due to lead sulphate crystals accumulating on the plates. The site I went to said to remove the acid and soak the plates with a solution of magnesium sulphate. They said it restores the battery to 70 to 80 percent of what the battery was new. I would do some homework before attempting. They didn't say what concentration of the magnesium sulphate to use.

The sulfuric acid in the electrolyte is the source of the problem, but the chemical reaction that is the actual problem is the creation of lead sulfate from the lead of the plates and the sulfur from the acid. This white semi-crystalline solid is electrically conductive and shorts out the the positive and negative plates across the ends of the bundles, or through deteriorating separators. The battery when fully charged has one plate of sponge lead sulfate, and the other of sponge lead. The discharged battery has both plates sulfated to near identical. The acid in the electrolyte is now nearly gone, and in fact the remaining acid is so weak that a dead battery can freeze. The battery rebuilders are few and far between today due to regulation, and the hit miss success rate of taking them apart, cleaning and chemical restructuring the plates to take a charge again. Sealed plastic batteries have made that even harder. So it will do no good to drain the acid, and it will be a nasty safety issue as well. I have repaired a cracked case (physical damage) with the acid removed from that cell, but it cost a pair of jeans and 3 hours. Jim

What you want to do will work some of the time, 30-50% it all depends on how the battery failed. Good acid is only half of what makes a battery a battery. To truly rebuild a battery the lead plates also need to be cleaned or replaced because they build up with sulfides as a result of electric current transfer (charging and discharging). They eventually get so plugged up that current can not pass through them. I do not know if/how it is physically done but I do know that you can buy a $1,000-2,000 battery resurrector that can do this electronically. A dead battery could also have dropped a cell. This is when a connection is lost inside the battery. The only way to fix this problem is to open up the battery case and re-solder the bad connection.

My concern is where are you going to put the acid which most likely have toxic lead particles that flaked off plates?

I've tried many things.

You can't raise the dead. NO magic snake oil.

If you want to try, get test equipment either a carbon load tester or conductivity meter and prove you improved the current ability of your battery. I have both testers.
What you want to do doesn't work or make major long lasting improvements.

The last thing I want is to be stranded in the middle of nowhere with a dead battery.
A dead battery that can't take a charge is good for one thing, a core charge about $10.

Rural King is my battery go to place. I find sealed batteries last longer. Less oxidation on battery terminals.

I worked at an old service station when I was in college in the 60s. We replaced more batteries when it was extremely hot or extremely cold. Just my observation. Don't have any internet link to prove it.

NO YOU NEED NEW ELECTROLITE what does the hydrometer reading show should be 1260

Rebuilding batteries is a hold over from the old days when they had tar sealed tops and could be opened up and new plates installed. I think some large batteries can still be serviced that way, only replace the bad cell, but basically what you are doing is saving the case. Not much gained there.

Places that claim to sell rebuilt batteries are in reality selling factory seconds, batteries that were changed out as a preventive measure, batteries that have been falsely accused and there was nothing wrong with it other than it was discharged, stolen batteries, or bad batteries they hope you will not bother returning.

Thanks for the info.
Dave

Sounds like it is more trouble than it is worth. Plus dealing with acid may be asking for trouble.

Aside: Is the build up of sulphates the reason a battery can indicate a full charge yet can't turn over a starter motor?

Other posters have this topic well covered .
Dont even try .
Battery explosions are loud ,
Dangerous and make a nasty mess .

I did that on a battery and it worked. I used the old acid from a newer battery that was cleaner. So I thought that I was on to something. I tried another four batteries and found out that I got lucky on the first one and quit wasting my time.