vented battery box

They let out a bit of hydrogen while charging. If not vented, this will rise, and you've the chance of being just like the Hindenburg. (Then again, maybe this would help lighten the rig - NOT!)

I know gas and propane fumes fall. Does anyone know if battery gases rise or fall?

They need to be vented out the bottom through the cabinet, and out the top through the cabinet.

The only place I have ever seen the RV type vented boxes are at the Dealer.

Keep in mind the Fifth Wheel storage area is under your bed in most cases so I would want to have any battery installed in that area using a vented box... You can use any kind of box you wish but you will need to tie the vest hose into the existing vent hose the other battery box is using to vent the bad fumes to the outside..

This GOOGLE VIEW link is many different type of battery boxes available with vent hoses...

PPL and Dyers comes to mind... Just click on the GOOGLE IMAGE of the one that catches your eye you might want to install. Just make sure the box will fit your GP SIZE battery you are going to use.. You could make up a pretty good battery box with vent and hose parts from LOWES.

VENTED BATTERY BOXES

Roy Ken

Here is a kit to retrofit a standard battery box...LINK
Looks like you could almost make your own..Hope this helps.
Just make sure you vent from the top of the box to the outside.