Battery vent is what I was thinking too Brian. Thanks everyone. Back cabinet door is standard as far as I know; I didn't order any custom cabinet work. I'm having it delivered; hopefully, very soon after completion. Have several dates booked this summer and a beach week later this fall. Will be going to EggCamping weekend in TN this summer. I can barely think of anything, other than the camper, these days. I have "Camping Brain Syndrome" really bad. Hopefully, it will be here soon.