04 Elantra Battery Smoking

My daughters Elantra's battery was smoking, it is dead now. She had it
jumped off last night but it did not charge the battery. Anyone know what
could make the battery smoke?

Rob

 

Something shorted. Could be the battery internally, could be some other
circuitry. I hope you disconnected it to be safe.

 

I concur with Ed. More than likely a shoert within the battery...


Steve

 

A single cell can short - sometimes without any visible effects. What then
happens when you start the car - again, a battery with a single, hard
shorted cell can sometimes still start a car - is that the charging system
is now charging a 10 volt battery instead of a 12 volt battery. The normal ~
14 volts usually gets divided among six cells - each with a charge voltage
of 2.33 volts - now gets 2.8 volts across it. This results in heat - lots of
it. You basically get boiling sulphuric acid.

 

Your alternator could be overcharging as well. If the voltage is not in
the range of 13.5 to 15.5V with the engine running, check the main slow
blow fuse. If it's blown, replace it. If not, look to replace the
alternator. Either way, you'll probably need a new battery. It sounds
like it's smoked. (Pun intended).

 

Lucky as heck it didn't blow up with Hydrogen gas being given off in that
smoke!!! I wonder how much sulphuric acid is spread all over the engine
compartment. It might pay to wash everything down with a weak solution of
baking soda and water. If you see if bubbling, you know it's neutralizing
the acid.