Battery venting [split from an unrelated thread]

I looked at the PurpleLine Caravan movers and I do not think I can get it this tight to the wall when storing the unit.

If you noticed, I had to relocate myself the battery box from inside of the slide-out. In the RV closed position it does not vent explosive gases when being charged by the tow vehicle. It vents the gases inside of the closed trailer. The TrailManor Plant Manager stated it is not TrailManor's problem since they did not provide the battery. If your TrailManor product does not have the battery on the outside, you have this serious safety issue.

American National Standards Institute (ANSI)/Recreation Vehicle Industry Association (RVIA) 12V - Low Voltage Systems in Conversion & Recreational Vehicles 2-3 Auxiliary Battery Installations. Storage batteries shall be securely attached to the vehicle. If provided battery compartments shall be vapor resistant to the interior and ventilated directly to the exterior of the vehicle.

[Bill]

Pete -

I am familiar with ANSI, and also with RVIA to which Trail Manor subscribes. You are right - both require that batteries vent to the outside. I don't know your unit, but I find it hard to believe that the factory design does not do this. Your battery is located in the front slide-out, under the sofa? I have never seen that configuration. And the battery box does not have a piece of flex hose leading to an exterior opening?

I would expect that your battery would be in the compartment under the rear bed, accessible from the outside. This compartment is sealed against the interior, and the battery is / should be vented through the sidewall of the lower box via piece of flex hose. When the rear shell is down, it does not seal off the lower box from the outside, and so is vented properly. All of the slide units with the battery in the rear are vented this way. If your battery is in the front, I have not seen the layout but I would expect it to be similar.

Bill

Bill,

Please take a look at the attached pictures. Do you still agree that the 12v battery is vented correctly to the exterior when in tow mode being charged by the tow vehicle? There is a wall blocking and roof sides blocking the exterior venting of battery gas.

I have downloaded ANSI and have been in contact with RVIA. I have not heard any response from TrailManor cooperate or the plant manager to remedy the safety concern since mid July to say that it is vented correctly. The Plant Manager stated that “it is not TrailManor’s problem, since TrailManor did not provide the battery. It is the dealer’s problem”.

Thus, I had to pay to have the battery box moved to the exterior of the RV comply with ANSI/RVIA 12V 2-3 Auxiliary Battery Installations “battery compartments shall be vapor resistant to the interior and ventilated directly to the exterior of the vehicle”.

I have attached pictures of my TM 2417 KS Sport for situational awareness. As you can see, the black battery vent when the RV couch slide is out is fine when camping. When the slide is in for towing, the battery vent is being blocked by the side wall (not venting the battery to the exterior). Also, closing both roof sections makes a closed interior space for the gases to accumulate when towing making it worse.

TrailManor Owner’s Manual: All TrailManor travel trailers are engineered to accept an auxiliary battery. Batteries mounted within the trailer must be sealed to the interior and vented to the exterior. The trailer’s battery will be charged also by your tow vehicle’s battery/charging system when connected.

Bottom line, if you can not see the battery vent when in towing mode, there may be a problem that needs to be addressed.

[LoveToCamp]

From your comment that one must be able to see the battery vent while in tow mode, I guess no TM nor the old Hi-Lo can have a battery inside the unit.

While my battery vent is on the side of my slide, opposite side of slide from yours, I haven't given it any thought until you brought it up. There is no way to vent to the outside while towing, as all exterior lower walls are covered. So, it made me step back and think about the "why".

The "why" is to vent hydrogen gas. I could not find information about how much hydrogen gas is created while charging, so that hurts in the information gathering. But, my supposition is that when we vent to the outside of the slide, the space it is going into is not airtight by any means. If we are driving and towing, there should be more than sufficient air turnover to eliminate any hydrogen buildup.

If we have a charger on the TM while it is closed, though, I can't make an argument for good airflow, as the slide is going to be a tight fit. Since the fumes rise, they would go into the TM itself. Left long enough on a bad charger, I guess there would be potential for the gas to build to a great enough level to blow it up, if there was an ignition source.

However, I have not seen any report of a TM or Hi-Lo blowing up while in storage (just because I have not seen a report doesn't mean it may not have happened, though). I have a solar panel on my TM, and have the panel exposed all the time. Even when my TM has been closed for a month or more (rarely happens, though), I have not had any problems. While I will continue to ponder this situation, I am not going to worry about it, nor will I try to vent the battery to the outside any more than it already is. I think that if it was a problem, someone's TM would have exploded, and there would have been a post on this forum. No news is good news.

[Padgett]

If concerned, why not just remove the battery when storing ?

Good discussion in the thread for the thread Factory/Dealer failure to communicate. I have asked TrailManor repeatedly about the battery situation, but they have chosen not to respond with a solution. Talking to RVIA standards, they referenced ANSI/RVIA 12V Paragraph 2-3. To have a safety standard defined, must indicate a safety practice to follow to prevent a safety incident. Ventilated directly to the exterior of the vehicle does not mean obstructed. You are correct with the hydrogen and oxygen battery gases produced flow upward, thus the requirement for the strict venting guidance and the certified battery case. Like you, I do not know the potential for an anomaly, but RVIA standards was very concerned. As for a trailer exploding, I do not want to put my safety or investment at risk. Thus a good discussion for other people to decide if they want to accept the risk.

I did remove the battery untul I found a safe solution.

Thanks.

[Bill]

Pete -

The second photo tells the story. Yes, it is properly vented. It is important to remember a few things. First, even if a battery is being improperly charged, it doesn't generate a hurricane of wind, with all the attendant back pressure. At most, it generates only a tiny puff over the course of hours, which requires only a tiny opening to vent.

Second, the sidewalls of the shells don't come anywhere near making an airtight seal on the walls of the lower shell. The bag seals themselves are very permeable, and air penetrates them readily. And whether we like it or not, there are numerous places where the bag seals don't make full contact. As evidence, look for posts on this forum - there are a lot of them - about dust penetration into the trailer. Dust couldn't get in if the shells were hermetically sealed.

Third, it is commonly repeated that hydrogen is lighter than air. This is true, but it is also irrelevant. If you have a closed, undisturbed container with some air in it and some hydrogen in it, the hydrogen will gradually rise to the top. But that is not the situation in a TM, especially when it is being towed. The continued swirling of air between the shells very effectively stirs the mix, so layers don't ever have a chance to form.

And finally, because of the air circulation in and out and between the shells, hydrogen can never build up to the concentration that is required for ignition. Hydrogen won't burn until the concentration reaches 4%, which would be a huge amount of hydrogen in the volume of the TM, or in the volume of the space between the shells.

All TMs are built with a vented battery box, with a hose connected to a vent through the sidewall. To my knowledge (not necessarily complete, I admit), the vent is always very loosely covered by the sidewall. RVIA inspects and approves all such vents at the design stage, and TM could not apply the RVIA badge if it were disapproved.

I can imagine that if the battery box itself were not vented, and if the cover fits in a nearly airtight manner, then it would be possible to have a problem in the much smaller volume of the box. But the battery box is always vented.

I hopes this helps clear up the issue. There is nothing wrong with adding extra venting to the battery box if it makes you more comfortable. But it isn't necessary.

Bill

[Padgett]

It appears that the RVIA document references the NEC specifically section 480 which says about storage batteries:
"Hydrogen is lighter than air and tends to concentrate at ceiling level, so some form of ventilation should be provided at the upper portion of the structure. Ventilation can be a fan, roof ridge vent, or louvered area."
also
"The fumes given off by storage batteries are very corrosive; therefore, wiring and its insulation must be of a type that withstands corrosive action"
and
"Overcharging heats a battery and causes gassing and loss of water. A battery should not be allowed to reach temperatures over 110°F, because heat causes a shedding of active materials from the plates, which will eventually form a sediment buildup in the bottom of the case and short-circuit the plates and the cell. Because mixtures of oxygen and hydrogen are highly explosive, flame or sparks should never be allowed near a cell, especially if the filler cap is removed."

So two key elements:
1) batteries, particularly those with removable caps, need ventilation
2) the battery should never exceed 110F

That said for a battery in the rear compartment a vent is needed near the ceiling or ducted to a point above the battery. Further so long as the battery is not allowed to become overcharged or reach 110F this outgassing rate should be relatively small and if allowed to disperse then there should be no issue.
(a pint of water can produce about 10 cu ft of H. If you need to add a pint exery six months (a lot) to the battery then it has outgassed about enough to fill a balloon.

My thought is that if there is a louver above the battery the gas will excape. For belt ans suspenders adding a louver with a water shield when moving will provide enough air flow.

If really concerned, add a bilge blower and use before lighting a fire.

[tentcamper]

I'm not sure the battery is installed by the factory??? I was under the impression that because of the various configurations that the buyers wants for batteries, that TM left it to the dealers to install the battery and boxes??

Which would explain why the factory does not want to commit on the battery or box.

[Bill]

Trail Manor does not provide the battery, but Trail Manor does provide and install the vent fitting through the sidewall that matches the standard vent hose from any standard battery box.

Bill