Sealing Lead Acid Car Battery.

[Richard_Electronics]

Hey well, i have a car battery VARTA A14 12v 40Ah CCA:330...
And for some reason its previous owner cracked opet 4 holes (it was Sealed Lead Acid Battery before he opened it) the plastic is cracked and there is no any caps for holes, i covered it with cloth made of synthetics so dust can't go in.
I need some advice how can i seal it again (i was thinking about using silicone and apoxy glue but im not sure will it come off or will start chemical reactions beacuse of acid).

 

[Mukund yadav]

You can fix by plastic sheet of majerment of that hole

 

[Tha fios agaibh]

You could use rubber. Perhaps corks if it's round.

Better yet, just buy a new battery. The money is worth the piece of mind of knowing you have a reliable battery, plus its not going to leak sulfuric acid all over

 

[kellys_eye]

And for some reason its previous owner cracked opet 4 holes

Sounds like they tried to 'rejuvenate' the battery using a technique reported across the interweb - removing the 'plugs' and topping the cells with de-ionised water perhaps???

Not entirely sure of the veracity of this process but the contents of the battery are very corrosive and the battery no longer meets the 'sealed' lead acid nameplate.....

It's not worth the risk to use it - although that's not for me to make the decision - so proceed with the utmost caution.

 

[Richard_Electronics]

Yea i know everything is best when you buy new but im trying to repair it.

The battery is pretty much new (bought from store before 3 months in that case there is no need for rejuvenate).

Previous owner has opened it because he wanted to charge the battery(he is old gen man and have never used fabric sealed batterys) those non sealed batterys had to bee opened because of presure inside (prevent explosion).

I wont use it in car or anything like that i wanted to use it for some "experiments" and projects but i don't want acid to spill all over everything.

 

[Dimitri]

Not entirely sure of the veracity of this process

Older car batteries, and even modern industrial batteries, need to be watered. As the plate and acid chemistry, causes the battery to be charged at a hotter temperature evaporating the water over time.

But modern "sealed" car batteries, are designed to keep the evaporated water in the cell, and let it condense back. Adding more water, as long as the battery hasn't been "abused" is far more likely to kill the battery quicker diluting the acid concentration. Very little to no water will ever leave a sealed battery using normal charging methods.

Hell I have seen sealed lead acid batteries bulge like a capacitor before the pressure is legitimately high enough to cause the pressure relief valves to allow the gases to vent.

Dimitri

 

[Richard_Electronics]

Older car batteries, and even modern industrial batteries, need to be watered. As the plate and acid chemistry, causes the battery to be charged at a hotter temperature evaporating the water over time.

But modern "sealed" car batteries, are designed to keep the evaporated water in the cell, and let it condense back. Adding more water, as long as the battery hasn't been "abused" is far more likely to kill the battery quicker diluting the acid concentration. Very little to no water will ever leave a sealed battery using normal charging methods.

Hell I have seen sealed lead acid batteries bulge like a capacitor before the pressure is legitimately high enough to cause the pressure relief valves to allow the gases to vent.

Dimitri

Question was how to seal opened lead acid battery. (stuff about charging is not important now) Thanks!

 

[kellys_eye]

Yes, seal it BUT, as I recall, the individual caps may have pressure relief holes in them so please ensure you have the same arrangement. (can;t be too sure - you would have to compare your battery to an original to see if you spot a small hole).

Plastic cement (glue) should hold a suitably shaped/sized cap in position.

 

[Richard_Electronics]

Oh damn i need something that will let air true but keep acid inside, like filter.

 

[Dimitri]

Question was how to seal opened lead acid battery. (stuff about charging is not important now) Thanks!

Short answer, you can't. You will either seal it without enough pressure relief and the battery will blow up on you. Or you will seal it not securely enough and it will vent.

There is a lot of math, and trial and error that battery companies use to get to the right numbers based on their lead and electrolyte formulations that cannot be replicated easily.

Dimitri