Just passing along an anecdote.
My wife & I were driving down the road in our comically problematic Dodge Ram.
She asked, "You smell that?"
Back & forth, it's us, it's not us. I pull over, pop the hood, can't see anything. Downwind of the fan, I can smell the smell. Upwind of the fan I cannot. Shoulder shrug. We're sort of nowhere so we decide to keep going to our destination.
Every time we slow or stop, the smell really comes through the vents. I'm starting to not feel too great.
We get where we're going. Smell is pretty bad. I pop the hood and still don't notice anything. Shut the engine (hence the fan). The main battery shows its hand. It's is emitting some sort of smoke or vapor. Because I trust American cars as much as I trust, eh... Ok, there's nothing I trust as little as an American car. Point is that I've got tools for tools in the back and immediately pull the battery. Got lucky as it was just starting to emit some liquids. Once pulled off the electrical system frantically trying to charge it, it calmed down and died a peaceful death.
If only our dead relatives could be turned in for a $22 core charge... Too morbid? BTW, how have battery prices doubled, yet core charges shrunk??
All of this is just to serve as a reminder that even your good old lead acid battery can ruin your day, be it a Dodge, a Honda (my weapon of choice), or <ObligatoryCanardContent> a Rutan Canard </ObligatoryCanardContent>. I wish I could describe the smell. Not quite tar. Not quite rubber. Not quite brake or clutch. Definitely something you'd like to avoid breathing.
Curious how many people have battery mounts / housings that vent to the outside...