I was driving home today from columbus, OH and i heard a hissing / air leak comming from somewhere behind me. I pulled over right away because i thought it may be a fuel leak, then i realize its comming from my passenger rear bin where my battery is located.

The battery is an Optima red top.

I couldn't really tell exactly where the air was comming from. The battery was hot, but not hot enough to burn me, i could hold my hand on it for 20-30 secs before it got too hot. After about 5 mins the hissing noise stopped and since i was on the side of the road i got back onto the highway, a few more mins down the road the hissing started again. I rode the rest of the way home with the windows cracked and the air on high because i didn't know what kind of gas was comming out of there. It didn't seem to smell at all.

I thought the Red Top was a sealed battery so that nothing could leak out? Does anyone have a clue whats going on here? One thought is that the alt is overcharging, but i haven't got my multimeter out to check it out yet.

 

My $.02 would be to get the battery checked.

Do you have PFC ?

 

I have an E6k, and i had my latop in the car with me but i didn't even think about checking it for the voltage, damnit, good call on that one.

 

Check all your wires from bay to bin.
Do you have a inline fuse on your "new" positive wire.

You should pop a fuse if its grounding out.
Hopefully thats not the hissing sound. If you do not have a inline fuse, I would think it pop another fuse .


Just brainstormin

 

The hissing is airflow, i can feel the hot air comming from somewhere in the bin, i not 100% sure that its comming from the battery, but its the only thing in the bin. I didn't think it this was possible for a sealed battery, not for over an hour anyway...

 

the alt seems to be sending the correct voltage to the battery, right about 14v, checked with a multimeter and verified though the haltech. What else would cause a battery to do this. The car starts fine, there is plenty of power comming from the battery. If the battery wasn't in the rear bin, i would have never noticed.

Anyone have ideas?

 

This has only happened when you're driving or when it's running? What about amperage to the batt? Only thing I can think of is the batt is being overcharged somehow. Based on the conditions that you're describing, that's all I've got.

 

I think it takes a while for it to start, maybe 1-2 hours of the car being on. What would be the best way to check the amps? I think i can only check 10a with my multimeter, and i'm guessing its going to be more than that.

 

Check the battery voltage while the hissing sound is being made. I had a problem on another car where the voltage regulator for the alternator was starting to die... it was putting out 17V. It took me awhile to realize this, and when I pulled over, the Optima battery was hot to the touch (and the battery was not located in the engine compartment). It cooled down, I fixed the charging setup, and life went on.

Take care,
Shad