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Rotten egg smell while driving.


Topic starter

Hello everyone - I own a 2019 Nissan Rogue that has 19,000 miles on it. I noticed a rotten egg smell while driving on the highway today, this is the second time I’ve noticed this. I open the hood and noticed a shiny liquid seeping out of the top of the battery. The battery is only a couple of months old, that is crazy, I’ve never seen anything like that before…. Could that be the cause of the smell and more importantly is this car even safe to drive with this happening?

5 Answers

The battery is bad and maybe your charging system too.

Any problems you have should go straight to Nissan for warranty work. Insist on a full diagnosis of the problem.


Would the battery light be on if there was an issue with the alternator?

Not necessarily if it's overcharging. If the vehicle is still under warranty don't mess with it yourself, make the dealer fix it.

Ok. Yes, it’s under warranty. I have a warranty until 125,000 miles. I don’t really know how to fix cars anyways, I tended to screw things up and cause more damage when I tried. I just wanted to make the post because I don’t know it’s super serious like a fire hazard or something.


Apparently, the voltage regulator has failed and is over charging the battery.  It needs to be replaced ASAP.  It is internal to the alternator.

Many modern systems are computer controlled now. A new alternator may not fix it. There are current sensors involved too.


Rotten eggs smell is caused by hydrogen sulfide. The battery contains sulfuric acid and lead. If it's overcharged, it can produce hydrogen sulfide. Sulfuric acid by itself has no smell. Sounds like your battery might be damaged or the alternator is overcharging it. Don't touch the liquid with your bare skin. Wear safety glasses, chemical gloves, and dissolve a little bit of baking soda in water. Dribble it on the liquid. If it starts reacting, it's acid. Figure out why it's leaking. 

This post was modified 1 week ago by Justin Shepherd

It’s like a Diehard Gold battery. I’m not sure if those are any good or not. It was just seepage, not very much. I wiped up some of the liquid with a paper towel, it had a pungent odor to it but I couldn’t really tell if it was the same odor that I was smelling while driving.

Posted by: @joey-lee

I don’t know it’s super serious like a fire hazard or something.

It's like getting medical or legal advice on the internet. Nobody knows. In order to know, somebody qualified needs to physically look at it, run tests, etc.  There's not really enough info here to advise you. I don't know if it's because the battery is bad, the alternator is bad, or you have shorts somewhere, etc. Fire is actually not entirely out of the realm of possibility.

I think it's bad enough to have concentrated sulphuric acid dripping around the engine bay. It is nasty, nasty stuff. Any metal it touches will badly corrode. Even the vapours in the air will start to attack everything under the hood. Personally, I would have immediately yanked that battery out as soon as I saw the seepage.

If I were you, I would be getting the car back to Nissan ASAP.

Topic starter

I forgot to mention, I wipe some of it off with a paper towel. It definitely had a pungent odor but I couldn’t tell if it was the same that I could smell while driving.