Battery Fumes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hcaz095 · 05-14-2009, 02:12 AM

So, when driving yesterday I noticed a smell of rotten eggs... thought it may be coming from the vents... couldnt figure it out. After stopping and sniffing my engine bay, i notice my batter is fuming out of one of the 2 vents on the top of the bat (made me feel great that I was sniffing in gaseous sulfuric acid)...the battery was very hot to the touch. I do not know when it was last replaced, but looks newer and the truck starts right up, even after this issue/ cooldown. The weather was 60 F, and I wasnt driving hard or for very long. I have never seen or heard of this before, but saw there is one other post, and the rust issues in this location it must not be all that uncommon?

Who else has had this happen? What should I do? What other problems may have led to this happening?

**El Jay** · 05-14-2009, 02:37 AM

Right off the top of my head, at this time of night; my thoughts would be look at the voltage regulator and overcharging.

I'm going to bed now.

Let us know what you find.

hcaz095 · 05-14-2009, 02:52 AM

I was thinking it was overcharging, although the batt/ amp guage reads good... havent put the voltmeter to anything yet though.

Or... I had a refillable lead-acid battery in a dirtbike as a kid... could it be low on water/acid? Current heats up what little is in there? I havent poked the battery too much yet... I've never even noticed batteries that have little vents for this... mine were always totally closed i thought...

~Zach

cdowns · 05-14-2009, 04:28 AM

good way to tell if the battery is low on fluid is to take the caps off and LOOK
i'd also look at the condition of your cables and take them off and clean them real good both ends of both cables

Woody · 05-14-2009, 05:55 AM

Your battery is venting because the acid/water in it is being boiled. This is from it either being over charged (most likely) or the Diodes in the alt. have failed and it is being charges with AC voltage ( this will kill the battery ) instead of DC voltage.

While your battery is venting as you described, you should be very careful around it!!! The gas vapor spewing out is extreamly flammable and a spark could blow up the battery!! Been there, Done that!

Don't trust the gauge in the dash, check it out with a meter.

**special-K** · 05-14-2009, 07:09 AM

Quote:

Originally Posted by Woody

Your battery is venting because the acid/water in it is being boiled. This is from it either being over charged (most likely) or the Diodes in the alt. have failed and it is being charges with AC voltage ( this will kill the battery ) instead of DC voltage.

While your battery is venting as you described, you should be very careful around it!!! The gas vapor spewing out is extreamly flammable and a spark could blow up the battery!! Been there, Done that!

Don't trust the gauge in the dash, check it out with a meter.

I have nothing to add to this.I had the same issue and went to an internal regulator type alternator which took care of whichever part was failed.

leos11104 · 05-15-2009, 12:29 AM

i had the same problem changed my battery and have been on the road over a year now with no problems

05-14-2009, 02:12 AM	#1
hcaz095 Registered User Join Date: Mar 2008 Location: Ann Arbor, MI Posts: 61	Battery Fumes So, when driving yesterday I noticed a smell of rotten eggs... thought it may be coming from the vents... couldnt figure it out. After stopping and sniffing my engine bay, i notice my batter is fuming out of one of the 2 vents on the top of the bat (made me feel great that I was sniffing in gaseous sulfuric acid)...the battery was very hot to the touch. I do not know when it was last replaced, but looks newer and the truck starts right up, even after this issue/ cooldown. The weather was 60 F, and I wasnt driving hard or for very long. I have never seen or heard of this before, but saw there is one other post, and the rust issues in this location it must not be all that uncommon? Who else has had this happen? What should I do? What other problems may have led to this happening?

05-14-2009, 02:37 AM	#2
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: Battery Fumes Right off the top of my head, at this time of night; my thoughts would be look at the voltage regulator and overcharging. I'm going to bed now. Let us know what you find. __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck

05-14-2009, 02:52 AM	#3
hcaz095 Registered User Join Date: Mar 2008 Location: Ann Arbor, MI Posts: 61	Re: Battery Fumes I was thinking it was overcharging, although the batt/ amp guage reads good... havent put the voltmeter to anything yet though. Or... I had a refillable lead-acid battery in a dirtbike as a kid... could it be low on water/acid? Current heats up what little is in there? I havent poked the battery too much yet... I've never even noticed batteries that have little vents for this... mine were always totally closed i thought... ~Zach

05-14-2009, 04:28 AM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Battery Fumes good way to tell if the battery is low on fluid is to take the caps off and LOOK i'd also look at the condition of your cables and take them off and clean them real good both ends of both cables __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

05-14-2009, 05:55 AM	#5
Woody Registered User Join Date: Feb 2000 Location: Georgetown, KY, USA Posts: 631	Re: Battery Fumes Your battery is venting because the acid/water in it is being boiled. This is from it either being over charged (most likely) or the Diodes in the alt. have failed and it is being charges with AC voltage ( this will kill the battery ) instead of DC voltage. While your battery is venting as you described, you should be very careful around it!!! The gas vapor spewing out is extreamly flammable and a spark could blow up the battery!! Been there, Done that! Don't trust the gauge in the dash, check it out with a meter.

05-15-2009, 12:29 AM	#7
leos11104 Registered User Join Date: Mar 2007 Location: colorado Posts: 66	Re: Battery Fumes i had the same problem changed my battery and have been on the road over a year now with no problems



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