Battery Venting

Short of forced air, I would not make such an assumption.. HOWEVER I can answer your question.. Density.

Now.. Fact is I do not know the numbers.. but I know that normally one of those vents is placed higher than the other... Air by itself will have a DENSITY that is different than air laden with battery fumes,,, I will not speculate as to if that density is higher or lower but the more dense air will naturally move down and the less dense air will naturally move to the top. this is why hot air rises, it is less dense (not lighter as most folks say, a kilogram of air is still a kilogram of air, but a kilogram of HOT air is a lot larger at the same pressure than a KG of cold air).

So it is natural convection that powers the forced air vent.

Get us a pic of that box set up.

Box should be sealed like this:

jefffoxsr wrote:
I was thinking about the AGM batteries and the companies I called say they will only off gas if they are overcharged. Do they still off gas a little bit though during normal charging?

Companies have to claim they off-gas for the sake of CYOA...

I'll dig for the link, but I recall reading technical data from DEKA East-Penn (Duracell / West Marine / many other brand-labels) showing their batteries only significantly off-gas during SERIOUS overcharge, like 15+ volts going into the poor battery at 70F.

I was thinking about the AGM batteries and the companies I called say they will only off gas if they are overcharged. Do they still off gas a little bit though during normal charging?

Replace the flooded cell batt with AGM, which offers minimal off-gassing

Hydrogen is 20 times lighter than air, it is going to go up.

Why is the battery in the living quarters while not in an air tight box, vented to outside ? That is not correct !

All the vented boxes I looked at before purchasing mine had one hole in the bottom and one hole in the top. I assume the air is expected to come in the bottom hole through the floor and exit out the top.

The concern is the hydrogen being vented (think of the Hindenburg)not much else matters.

My vented battery box is completely sealed with a weather tight lid and where cables come in/out and the only opening is the outside vent and a couple of drain hole in the bottom of the battery box to drain off battery fluids to the ground.

I use an electrical PVC junction box with a weather tight cover and a large 2-inch hole cut in the middle of the box to route my cables to the battery box... My battery cables are routed to my battery switches and fuse blocks etc using flexible PVC conduit.





I suspect that any fumes being vented by the batteries will escape to the outside via the larger outside air vent.

If you have large holes cut into the sides of your battery box for cables then I suspect you will get fumes inside your battery box area.

My 5th wheel trailer has a sealed battery box in the pass through storage area but my off-road popup trailer has a regular non-sealed snap on lids with large openings mounted on the trailer tongue.

Roy Ken