My Coachmen Freedom express has been plugged in since I de-winterized it in April, the battery (new in 2014) was stored in the garage (heated) over the winter. Over the last week I've noticed a sulfu...
check your converter. Mine was a bad converter boiling the batteries = sulfur smell.
One capacitor was shot, literally. It looked like someone shot it with a 22! So the remaining one could not regulate itself and boiled out the battery.