Battery box venting - does the industry have this wrong?

[Yoda]

Hydrogen sulfide gas is very very dangerous. When charging flooded batteries this gas is produced. I have personally witnessed a battery explode (no one hurt) Hydrogen Sulfide IS HEAVER THAN AIR So why is the vent system forcing air into the battery box, but there is no real positive exit except into the front bay of my 5th wheel through the typical cable holes on our boxes? This is not much better than having the battery's in the open. Logic would say to have a vent out of the bottom of the box. I ran across this today in re-searching battery box venting.

My plan for my new installation is to have a vent out of the bottom of the box.

Thoughts?

Yep - I know go back to my corner

Hoping for a good discussion on this and solution folks can use.
Keith

[Jlawles2]

Keith, I think the box is supposed to be vented on the bottom also. My current unit (not a GD yet, next weekend hopefully) has the battery box in the front compartment vented out the bottom with an air intake on the wall. This is to ensure that the heavy gas either exits on its own, or gets forced out the bottom.

Pure hydrogen (also a product of charging i think) will exit out the top if its not under positive flow.

[Yoda]

Keith, I think the box is supposed to be vented on the bottom also. My current unit (not a GD yet, next weekend hopefully) has the battery box in the front compartment vented out the bottom with an air intake on the wall. This is to ensure that the heavy gas either exits on its own, or gets forced out the bottom.

Pure hydrogen (also a product of charging i think) will exit out the top if its not under positive flow.

You are correct about the hydrogen gas.. I have 2 battery boxes and need to double check the venting out the bottom. I know for sure one does not.
Thanks for you input on this.

[Jkwilson]

Hydrogen sulfide gas is very very dangerous. When charging flooded batteries this gas is produced. I have personally witnessed a battery explode (no one hurt) Hydrogen Sulfide IS HEAVER THAN AIR So why is the vent system forcing air into the battery box, but there is no real positive exit except into the front bay of my 5th wheel through the typical cable holes on our boxes? This is not much better than having the battery's in the open. Logic would say to have a vent out of the bottom of the box. I ran across this today in re-searching battery box venting.

My plan for my new installation is to have a vent out of the bottom of the box.

Thoughts?

Yep - I know go back to my corner

Hoping for a good discussion on this and solution folks can use.
Keith

Hydrogen is produced when a battery is charging, not hydrogen sulfide.

[Country Campers]

My Reflection 29RS has a vent hole in the bottom of the battery box.

This discussion got me to remember when my neighbors tried to make hydrogen gas. They had some kind of plate stuck into a box of water and added battery power to the plate and produced hydrogen in a plastic bottle. Nobody was ever hurt during these experiments , even when we made fuel out of fermented corn ( farmers have a lot of time to think up strange things to do while plowing and planting).

Brian

[Cate&Rob]

Yoda
Hi Keith,

I think everybody is correct . . . well, except maybe Brian who is off in the corn field experimenting .

A lead/acid battery charging normally produces hydrogen which is lighter than air. A battery being seriously overcharged can break down and produce hydrogen sulphide which is heavier than air. Battery ventilation systems should provide exit paths up and down for either gas and for naturally purging air flow. My OE battery boxes have an opening in the bottom and a vent hose from the top.

A really good source for answers to any battery related questions is https://batteryuniversity.com

Rob

[Guest]

X2 on Robs suggestion,

Batteries also generate heat when charging and discharging if the load is high enough. Heat rises which aids the flow of hydrogen gas to exit at the top. Inflow at the bottom aids in flow at the top.

I remember when the hydrogen generators were being made by folks to increase fuel economy in cars by using electrical current (alternator) to break down water into hydrogen gas. The problem in doing this is more energy is consumed to make the gas than any measurable improvement in fuel economy.

Jim

[Yoda]

I am learning new things again - could be dangerous. In my box search I was looking at the venting. Almost all of the box makers for the 6V GC2 battery's say the box is vented (just holes in the top). None have holes in the bottom, but claim to catch acid spills. The Century Plastics one is a pretty tight sealed box with no factory vent holes that I can see

I have been cruising the web looking at lots of battery and battery box pictures. Very few folks have proper venting for their lead acid batteries.

Now in looking at my brand choices and just about every other battery box out there , why no provision for bottom venting, or a circular opening for the top vent?

Makes me wonder how much the average RV owner knows about this. The upside is this is helping me choose my box. Probably the Century Plastics one. With its flat surface I can easily get the venting installed. I need to remember to put a bug screen on the bottom one to prevent our local wasps from plugging it up.

Thanks for the discussion folks.
Keith

[Guest]

I recall someone had posted pics awhile back of their vented battery boxes. I believe it was Rob?

Jim

[Tom in PGH]

Our 303 has an intake type of vent on the front wall, and a pipe that leas to the battery box. I’ve never had the battery out of the box but, if I look at the underside of the unit, I can see that there is another vent pipe, the same size as the upper, that comes down through the coroplast (never tried to spell this, it may not be exactly right...)

[Yoda]

Our 303 has an intake type of vent on the front wall, and a pipe that leas to the battery box. I’ve never had the battery out of the box but, if I look at the underside of the unit, I can see that there is another vent pipe, the same size as the upper, that comes down through the coroplast (never tried to spell this, it may not be exactly right...)

That's how they are supposed to be vented. I double checked mine and the factory box is the same way with top and bottom vents. Its the second battery box the dealer installed that missing the bottom vent. I have my new quad box on order. First thing I will do is get the venting correct.

Thanks for checking
Keith

[d2reid]

Ya'all engineers and scientists don't laugh at me too hard. I had one RV that had a vent out the bottom and another that did not. I assumed the one with the bottom vent was to let the water out when I spilled it topping my batteries off.

Then I read that batteries gave off hydrogen. No problem, I remember that when the Hindenburg flew it had hydrogen in it lighter than air, so it goes up. Just don't smoke around it.

Now I learn about Hydrogen Sulfide. It's heavier than air and flammable. Oh boy! The good news is it stinks, so you can detect it with your nose. Ok, fore warned is fore armed. Next time I do my battery maintenance I will apply my drill and make holes in the bottom of the boxes and bay. I might even put a little plastic tube in to keep the acid water from corroding the bay floor.

Now I would like to learn about the probability of disaster. I have read many times that old batteries can and will explode if overcharged. So right up front you have two conditions, old, overcharging. What about batteries in good shape that are just charged by our converter's, what is the likelyhood of them exploding? 65 years old and I have charged a few batteries, I have never seen one explode. Is it the build up of gas that makes them explode? Do people leave the caps on while charging old batteries?

Ok, for further humor and jocularity amongst the well educated I am going to put forth my PPM theory on RV battery venting. It's my theory that my Momentum front bay and my battery boxes are so leaky that it's impossible for enough hydrogen (hydrogen sulfide) gas to build up to sufficient parts per million to cause an explosion. Not saying that it couldn't happen, just not very likely. And then, if it does have enough gas there has to be an ignition source, of which I have not found any, I guess maybe if there is an electrical short, but in the years I have been with RV's I have not seen any in the front bay.

But this discussion has also reminded me that it's time for me to take my 6v golf cart batteries into a professional shop and get them a deep discharge/charge.

[Guest]

d2reid Dallas,

I've never heard of a battery exploding due to overcharging where I've seen them run dry. But with high concentrations of hydrogen in this case, ignition may just be more probable. Explosive levels of hydrogen are as low as 4.2% in an enclosed area.

I've seen one fellow who exploded a battery while connecting battery cables and after that I blow over or fan a rag over the battery before making the final connection.

Jim

[Tom in PGH]

How timely. Here is a link that was in the RVTravel newsletter, this morning:

https://www.rvtravel.com/rv-electric...battery-level/

[RGEarley]

I am learning new things again - could be dangerous. In my box search I was looking at the venting. Almost all of the box makers for the 6V GC2 battery's say the box is vented (just holes in the top). None have holes in the bottom, but claim to catch acid spills. The Century Plastics one is a pretty tight sealed box with no factory vent holes that I can see

I have been cruising the web looking at lots of battery and battery box pictures. Very few folks have proper venting for their lead acid batteries.

Now in looking at my brand choices and just about every other battery box out there , why no provision for bottom venting, or a circular opening for the top vent?

Makes me wonder how much the average RV owner knows about this. The upside is this is helping me choose my box. Probably the Century Plastics one. With its flat surface I can easily get the venting installed. I need to remember to put a bug screen on the bottom one to prevent our local wasps from plugging it up.

Thanks for the discussion folks.
Keith

For what it’s worth, … I know I am late to this discussion, but maybe it will shed light for future readers: I had similar questions about a second battery box I wanted to add.. (I’ll be posting to another thread with questions about that, but not directly related to this one). Puzzled about what to get, I went to the local GD dealer where I bought our rig, and they sold me what looks like a box identical to the one in our 2021 Reflection 150 260RD. The top and bottom of this case are identical, and each has a hole sized to fit the vent tube. The pre-installed box had no attachment to the bottom, and a hose connected to a vent hole on the front of the compartment the battery box is in. The box I purchased came with a hose and a cover for the vent hole to attach to the hole in the wall and the vent tube. It came with no tee to connect the 2 hoses, but I got one at Ace hardware I think will work. The hose size seems to be an odd duck, it fits over 1 3/4” PVC pipe (but not over a tee for 1 3/4”).