Battery has a hisssssss

I had one blow up , sounded like a shot gun going off.

 

i was told by our old battery rep. that a every car has a atomic bomb under the hood.the battery. produces the same gas that that we dropped on japan.

 

..no punk intented....To much volts going to the battery.....a car bomb ready to explode...

 

Straight question; How would the situation differ with a sealed battery vs. the older style removable caps? Venting in the old ones doesn't help? Or if it is the escaping gas that ignites, would a sealed battery not explode?

 

All batteries have some sort of over-pressrue vent. An overcharging "sealed" battery, with a small vent would become pressurized, creating the potential for an even LARGER EXPLOSION.