Tar Top Battery

[Richard G.]

My Tar Top Battery is probably getting up to 3 years old or thereabouts. I bought it from Restoaration Batteries. I leave a battery maintainer on it most the time. It still hold a charge fine , but it has started leaking around one of the terminal posts. I had it out of the car and on the maintainer on the bench and the whole battery top is covered in battery acid, I can see it bubbling out of the tar about 1/8 inch out from the post. I know battery gas is explosive, but can I maybe cover the caps and use a heat gun and try to seal it up or am I going to blow my shed down the street messing with this battery? Logical thing to do I guess is take it to a battery shop- but hard to find anyone in Perth that has ever seen one before. If I can't fix it, I'll take out the innerds out and put a no maintenance battery inside, but I'd like to fix it if I can. Any tips appreciated. Thanks

[Willard M.]

Re: Tar Top Battery

I wouldn't fool with a battery that appears to have critical problems. On my 64 FI coupe I used to worry about my battery, particularly with hot starts. I put in an Optima battery and just ordered a top cover from Corvette Central so that it will look like a tar top with a quick glance. Probably wouldn't make the judges happy but I can now relax when it comes time to start the old girl.

[Jack H.]

Re: Tar Top Battery

When these batteries were built, the tar was applied hot and there was no danger of explosion. Of course, the plates and posts inside the battery were 'dry' (no water + H2SO4) meaning there was no threat of stray hydrogen.

Now, your battery generates stray H2 as a consequence of the charging process. Peak H2 generation runs in lock-step with peak charging. When the battery is either sitting idle or is removed from the car, there's very little stray H2.

BUT, you can STONE the issue by (1) removing the battery from the vehicle, (2) removing the cell caps, and (3) draining each cell of its acid/water electrolye. Now, there's no enabling agent to generate stray H2...

However, you do NOT want the battery to sit long in this condition. You've removed the caps + the electrolyte and the copper plates within each cell are now exposed to the atmosphere. That will allow them to grow oxidation with time!

So, if you do due diligence here (do all the work quickly--say in a morning or afternoon), I don't expect you'll do appreciable harm ESPECIALLY if you insure the battery is fully charged BEFORE you drain the electrolyte. With this move, you're simulating the factory original 'dry charge' sequence that was done to make it possible to ship batteries from the factory to the market without water/acid fill and avoid contact plate oxidation...

[Paul S.]

Re: Tar Top Battery

Just Installed A Repro Battery From Antique Battery From Hudson,oh.thier Battery Is A Sealed Unit That "looks" Correct. I Believe It Is A Gel Type Battery, So There Are No Acid Fumes Or Leaking Possible . The Instructions Do Not Call For Any Constant Charging With A Battery Tender. I Am Happy So Far With It.

[Louis T.]

Re: Tar Top Battery

Hi Jack,

Excellent post! A couple of follow-up questions:

Would one need to somehow air out the battery after draining it, or rinse it out with distilled water, before beginning the repair process?

Would leaving it filled with distilled water during repairs help retard the oxidation process?

What material container should the used acid/water electrolyte be stored in?

Should one reuse the acid/water electrolyte or purchase fresh battery acid? If fresh, how does one dispose of the old stuff?

Thanks.

Louis

[Jack H.]

Re: Tar Top Battery

[quote=Louis Trohatos (40341);429980]Hi Jack,

Excellent post! A couple of follow-up questions:

Would one need to somehow air out the battery after draining it, or rinse it out with distilled water, before beginning the repair process?

Not really, with the electrolyte drained and the caps off the cells, there's negligible free H2 around.

Would leaving it filled with distilled water during repairs help retard the oxidation process?

Yes, and that's an excellent suggestion!

What material container should the used acid/water electrolyte be stored in?

Remember high school chemistry? A good glass or plastic container will resist H2SO4...

Should one reuse the acid/water electrolyte or purchase fresh battery acid? If fresh, how does one dispose of the old stuff?

Yes, reuse the original electrolyte. Once filled, the acid portion does NOT age/go away... You only have to replenish H2O in a battery.

On disposal, I'm not a 'tree hugger'... For this MINOR amount of acid, I'd simply step outside my back door at 7930 feet overlooking the City of Denver in the non-populated mountain forest of Colorado and dump it. I'm sure the EPA would have a different opinion though!

[Rob M.]

Re: Tar Top Battery

On disposal, I'm not a 'tree hugger'... For this MINOR amount of acid, I'd simply step outside my back door at 7930 feet overlooking the City of Denver in the non-populated mountain forest of Colorado and dump it. I'm sure the EPA would have a different opinion though![/FONT]

He Jack, what about those thirsty elks around your house? We don't want to poison our future food would we???

greetings,
Rob

[Jack H.]

Re: Tar Top Battery

A little battery acid in the intestine track does NOT spoil the meat IF you're quick to field dress a fallen Elk 'buddy'...