Where does a battery off gas from?

[Cdash]

With all the talk I read about battery upgrades with flooded lead acid batteries, off gassing is always a concern to be dealt with. I believe many of us struggle with room and the availability battery boxes that will actually fit where we want to put them is limited at best.

That conundrum got me considering - where does the off gassing come from? I suspect from the individual caps, since the batteries are otherwise sealed.

Where I'm headed with this is the thought of venting the batteries without being sealed in a full box. Thinking a tray below the batteries that would contain any acid spillage, then a hood over the top of the batteries that is vented to the outside. This hood would cover as much of the batteries as possible and cover ALL the caps. In my mind, this would serve the intended purpose while still allowing me to place 2 batteries in the existing battery compartment.

Thoughts or comments, or am I just plain crazy?

And I do realize that AGM's are an option that could avoid this, just thinking outside the box a bit. (Pun intended).

[Paintinfool3]

well you could vent the area and possibly mount them in battery boxes with venting to outside from them

[Jmooney]

Not sure if you have room, but I bought a plastic utility box and hose vented the lid out of the existing vents in the ft of my 5er.

4 12volt batteries, in self contained box. Vented outside

Pic on my profile

[us71na]

As a lead acid battery is charged, Hydrogen and oxygen is released in each cell. This gas needs to be vented so it doesn't accumulate, because it can burn and in a confined space can produce an explosion if there is a spark. Battery compartments should not be air tight.

[ALJO]

There are special battery boxes available who can be vented to the outside with a 1 1/4 sum-pump hose. They used to be white but I am sure they can be any color and can have snap on clips for the lid.

[RoyBraddy]

The venting and over flo comes from the battery caps...

This is how my battery is vented in my fifth wheel...



The venting fumes are very corrosive like you see around your truck battery metal frame work and you need to get the fumes vented outside.

Also sometimes the batteries will boil out fluids by being over-charged forlong period of times and this fluid is also very corrosive. My battery box has a drain that extends down to the ground under my fifth wheel trailer...

Roy Ken

[Jagiven]

There are little vent slots in the caps.

I would recommend holes in the bottom of the plastic battery boxes, as they tend to fill up with rain water, and yes rain water.

[ALJO]

Roy; That's the one I installed years ago. It is a solid battery box and will install in any convenient compartment.

Some battery boxes doesn't have problems with water getting in the box. Some with the open top vents do. You can install a modified homemade vent in them (like a u-shape hose glued and silicone).

I would not recommend drilling holes in a battery box with regards the acid spills (very corrosive). It would be the same as installing a battery openly in the battery tray.

[RoyBraddy]

ALJO - My battery box in the 5th wheel has a flat plastic nipple in the bottom floor that has a small hose that routes down thru a slot opening in the floor. This will drain any boiled out fluids directly to the ground with out running across anything metal...

My three battery cases across the tongue of my OFF-ROAD Camper have holes drilled in the bottom of the case to drain directly to the ground. I have only had one incident where fluids boiled out which destroyed my battery (that is when I had four mounted) and after I installed a smart mode converter/charger setup in my 2008 model I haven't that problem since.

I do get rain water in my battery boxes as I am using the standard WALMART case lids that have two large openings for the cables to go through. You wouldn't think these would let rain water get in but it does...



I used to four of these cases across the tongue lined up...


Roy Ken