Replumbing tank vents in 5th Wheel

[Indy Tim]

I'm looking at buying some Lithium Life04 batteries and locating the behind the fake wall in the pass through (aka Rats nest). The vent for the gray water tank angles off at about 45 degrees and take a lot of space that could be used for the height of the batteries. Has anyone replumbed this or any other of the drain to vent lines to make this space more usable? I did see where someone caped off the tank vent directly above the tank and tied the vent into the washer drain line to use this as the vent. Not sure if this works well when washer is draining (see second pic).

[Country Campers]

The only thing that I can think of to watch out for is slope. You will want some kind of slope in the vent line back to the tank so it drains. I think the only reason that 45 degree angle fittings are used is because that is what is readily available and manufactures need to make plumbing easy. A steeper angle in the vent pipes will also provide better venting as the air will move upward faster or easier, less likely in a vent that is closer to horizontal. If you try this and get bad odors you will know then that a change needs made.

Brian

[Calbar]

I'm looking at buying some Lithium Life04 batteries and locating the behind the fake wall in the pass through (aka Rats nest). The vent for the gray water tank angles off at about 45 degrees and take a lot of space that could be used for the height of the batteries. Has anyone replumbed this or any other of the drain to vent lines to make this space more usable? I did see where someone caped off the tank vent directly above the tank and tied the vent into the washer drain line to use this as the vent. Not sure if this works well when washer is draining (see second pic).

If it's just a vent I would plumb it straight up to the floor and over at 90 degrees. It's a vent pipe so no need for drainage slope and it is perfectly fine in residential plumbing to have nearly horizontal vent pipes.

Rob