Chris commented... "Batteries should never be hooked up inside the passenger compartment as they off gas hydrogen while charging. One word? Hindenburg."

While I don't disagree, I wanted to note that in my '75 Avion the house battery stock location is in a metal box with a foam sealed lid, that is vented by an inch and a half diameter tube that exits less than a foot away behind the license plate.

Question: Is this stock arrangement dangerous?

Thank you!
Dave