When I started my 66 today I heard a loud bang. I opened the hood and the battery had exploded. The battery is about 6 months old and has caused no previous problems. Any ideas why it exploded.

 

probably the vents were plugged up and caused chemical reaction of the hydrochloric acid
causing the explosion.

 

You better mix a gallon or 2 of water and a box of baking soda and give everything a good bath. That acid will do some bad things if you don't.

 

Sorry to hear about your battery, I feel your pain. I would have to think that a Loose connection: internally or externally caused a spark. I have seen loose connection from battery post to plates inside the battery cause a spark when you hit the key. Check positive post to see if it is loose/twists inside the case.if anything that was grounded touched it that would def cause a spark.. I would clean everything that got acid on it with baking soda and lots of water to neutralize the acid. Charging causes Sulfuric acid gas Which is highly explosive in closed container e.g. battery case, but I would think you need a spark to set it off.

 

Overcharging likely produced excessive hydrogen. Probably ignited by internal or external short.

 

What kind of battery? So far the assumption is that it is a wet lead-acid battery.

The off-gas is hydrogen; however, there has to be an ignition source (spark) to ignite normal concentrations of H2 gas. Above about 8% H2 can ignite without an ignition source, but 8% is not easily reached.

It seems to me that you might have a bad connection that resulted in significant battery discharge combined with a connection heated enough to produce an ignition source.

Any damaged connections close to the battery?

BTW, I second the recommendation to use lots of fresh water and baking soda. Sulfuric acid sprayed on you underwood can lead to lots of damage and problems.

Sorry about your troubles.

 

Textbook case.

Dan

 

Thanks for the replies. As far as I can tell there is no damage to anything under the hood. The terminals were all tight. I did notice that the heater blower motor's wire was not connected and was making contact with the negative battery terminal. I don't know if the blower motor wire was like this before the explosion or if it was loosened and fell on the terminal from the force of the explosion.

I returned the battery to the auto parts store and was given a new battery due to the warranty. I put the new battery in and it started and drove just fine.

I should have mentioned that I had been on a lengthy morning drive and stopped at home depot for a few minutes. It was when I went to start it in the home depot parking lot that the battery exploded.

 

Wow, you lucked out.

 

Remember the Hindenberg Airship exploding in New Jersey in the 30's. Same thing only bigger. You are lucky your battery didn't explode in your face. I am happy that you never received any injuries.http://www.airships.net/hindenburg/disaster

 

Back in the 70's I had a Datsun 210 that the battery exploded in. It was a big explosion. The battery split and the top blew off, battery fluid went everywhere. It scared the s... out of me.

 

I had the same thing happen to my 427 '66 this summer. It was a Delco battery (wet cell). I have not replaced the battery yet but I did wash the engine compartment with baking soda and water.
It blew when I turned the key.

 

I had a Group 31 Interstate battery that was over 5 years old blow up this past June on my Blackfin boat. It sounded like a grenade. It was confined to a battery compartment so the mess was easy to clean up. Five boxes of baking soda. I spent hours on the Internet researching this. I could not find one example of an Optima battery blowing up. I found several examples of it swelling and short life. I now have Optima's in my 66 and boat.

OP, make sure you wash down everything as the acid goes everywhere.

 

Another Blackfin owner - there aren't too many of us left. We must both like things that are overbuilt with fiberglass.

 

Until you cook the new one. Remember, this happens not from defective batteries (although that is not unheard of-it is the exception not the rule) but from a failed voltage regulator allowing the alternator to overcharge, creating excessive hydrogen gas which lingers awaiting a source of ignition.

Engine running at high idle you should not see more than 14.5 volts across the battery terminals. 15 volts + turns into 17 volts + while running down the expressway. This cooks batteries and leads to acid leaks, bulging cases and sometimes, kaboom!

Original Delco mechanical regulators do not last for ever, eventually those field contacts stick and at some point they cannot be cleaned up. The mechanical replacements are woefully lacking in contact quality over the originals, making the solid state replacements using an original cover the best way to go short of a NOS.

Unless you have an NCRS gold trophy nationally award winning NOS or original voltage regulator whose absence will devalue your car 50% or more...replace your regulator. Otherwise you can always bring the 50% of the car that didn't burn up to the next NCRS event and request partial judging. If the car burned because of a genuine Delco regulator it might be worth some points.

Dan

 

You are right about being overbuilt. Mine is one of the last made (1997) and it is the Sportsman 27 with twin Yanmar diesels. They made about 8 Sportsman with diesels. I have 2500 hours on the engines now with zero issues. I have caught White and Blue Marlin from it and we are getting ready for the stripers. It is a great boat. What do you have?

 

This picture was taken last summer while I was taking my grandsons for a ride around the Lynnhaven River. The Lynnhaven bridge is in the background. The Chesapeake Bay is on the other side of the bridge and the Atlantic Ocean is 5 miles to the right of the bridge. Frankie should recognize this.

 

MarkC, they do explode. I saw it, did experience it and look at this link

http://www.fordgtforum.com/forums/sh...loding-battery



Typically caused by using an 50 amp jump starter but they do go up BIG.

 

I believe you. the link isn't working. Back in June, I also talked to the local Interstate distributor owner. I asked him if he had ever seen an Optima blow up. His answer was no. He sells lots of Optima's and Interstate's. He said he has seen lots of Optima's come back but none that blew up. I am sure there are more examples but at the time I could not find one.

 

Thanks everyone for the advice. I cleaned the engine compartment with baking soda and a power washer. I measured the voltage across the battery terminals at idle. It was just over 17 volts! I guess it's time to replace the voltage regulator.