Smoking/Stinky battery

I had a similar problem last year, at my year 2 of ownership. Just rotten egg smell, not smoking or dripping of liquid but battery did get hot. In my case I neglected to check the battery water often enough, it can dissipate and when low cause these type problems. Looking at top of battery you can see 2 caps that can be pryed off, use only distilled water and fill just until you can't see a space at the bottom of the tube. In my case, the battery was nearly completely dry, and ruined as it sounds like yours is. $100 lesson in my case. Google how to check the battery water.

Please be sure to disconnect from shore power and let the battery cool before you handle it, eye protection and gloves are a good idea also. If the water isn't low you may  have a charger issue. An auto parts store or your rv dealer will likely take the battery when you purchase a new one.

If you are within a year of purchase it may be a warranty item.