Check out the NOCO brand of battery boxes on-line- They use to have a couple of models designed especially for the GC2 GP24 DUAL 6VDC Golf Cart Batteries. You can modify almost any of the lids for these boxes for venting to the outside using hoses and a vent head. Lowes carries such items... If you find a suitable NOCO brand dual battery box you like you can probably purchase this thru AMAZON...
Batteries do vent fumes when being charged that needs to vented to the outside of the trailers..
My fifth wheel uses a depressed area just inside the front door of the basement area. It has two battery vents on both side. It also has a rail where the batteries are that will drain to the ground if the battery boxes fill up with water or battery fluids... My 5th wheel bedroom is just above this area so it was very important to me to have vented battery compartment as well as the Propane compartments mounted on both sides of the trailer in an enclosed area in the same area.
Never really liked the idea the batteries and propane were almost directly under the sleeping beds.
My other pull trailer has the propane tanks and the batteries on the outside tongue area.
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS