Vented Sealed Battery Box? (Box Ventilation Requirements)
They need to be sealed. One reason for sealing a battery box is to prevent theft. Another is to prevent damage to the battery. However, sealed does not mean air-tight and there should be enough vent holes to make sure there is no hazardous gas build-up.
Ventilation is required for two main reasons. One is to prevent overheating. The other is to prevent a build-up of hydrogen gas. This flammable gas can cause an explosion if it is not vented out of the battery box. You should have multiple vent holes to make sure your battery is safe.
To learn more about vented battery boxes and their requirements, just continue to read our article. It has the information you want to know about so you can have the right battery box installed on your RV or travel trailer.
Sealed Battery Box 101
What Does a Battery Box Do?
The duties of a battery box are quite simple. These boxes are designed to protect your battery from several incidents that could damage it. Those incidents could be water or acid spills, free-falling cargo or debris, and so on.
Many of these boxes are made from heavy-duty polypropylene materials but there is some leeway in the construction materials you can use. As long as you have the proper vent holes, you should be fine.
Sometimes those vent holes can do double duty and act as cable access holes. As long as there is good airflow, you should not be at risk at any time.
Do You Need a Battery Box For a Sealed Battery?
This is a good idea. It is said that a sealed battery is not necessarily non-spillable. What that means is that some of the acids inside the sealed battery can get out at some point in time. The battery box will contain that acid spill so it does not do any further damage.
Also, a sealed battery is still vulnerable to the elements. Water, rain, sunlight, etc., all can do damage to the battery or shorten its lifespan. A battery box will provide the necessary barrier that will protect your expensive battery from damage due to those elements.
That is not all the battery box protects the battery from. Sometimes, someone forgets to secure other pieces of cargo and in a quick stop or accident, that unsecured cargo can fall into the battery and damage it.
When the battery gets damaged it can lead to an acid spill that creates further problems. It is best to be on the safe side when it comes to batteries and make sure they are protected from all sources of harm.
Battery boxes are lightweight and do not tip the scales so much that you have to sacrifice anything important to have them on board.
Does a Battery Box Need To Be Vented?
Yes, they should be vented. As described earlier, one of the dangers that come without vents is an overheated battery. When it overheats, you can have a lot of problems and lose your electrical source for your DC-powered items.
Plus, when you go to charge your batteries, hydrogen gas will be created. This gas needs to be vented for it does not take much for it to explode and cause a lot of damage. The different RV discussion forums are filled with stories of how batteries explode during charging.
This is something that is easily prevented if you have the right type of vents on your battery box. For a properly vented battery box, there should be vent holes on the top as well as on the bottom.
These vents will not interfere with you being able to seal the battery box and lock to prevent theft. Besides hydrogen, an overcharged battery can produce hydrogen sulfide, another dangerous gas.
This gas is heavier than air and would need bottom vents to make sure it gets expelled from the battery box before it does any harm.
How do You Make a Vented Battery Box?
This is not really a difficult task if you have carpentry skills. One method simply puts together 5 pieces of 3/4 inch plywood into a box and you are just about done. It is best to waterproof the inside of the boards first before you put them together.
There is a lot of good waterproofing materials you can use for that part of the project. The 5 pieces cover the 4 sides and the bottom. The top is left open for venting. Then you would need to drill a couple of lower vent holes as well as a couple of holes for the battery cables.
Another way to make a battery box is to buy heavy-duty plastic bins and put your batteries inside of those. You can seal the cover or leave it off if you want. But if you use the cover, you will still have to put holes into the plastic bin to make sure it is properly vented.
Putting holes in plastic takes some care as plastic can easily crack. Plastic bins would be the cheapest way to go and you do not have to worry about gluing and screwing the sides together.
Vented Battery Box Ventilation Requirements
We found no real government regulations governing the venting of RV battery boxes. The most serious mention of vents is a highly recommended piece of advice and it is good advice to follow.
It is just common sense to put vents into an RV battery box as it is a safety issue no matter how you look at it. Most RV battery boxes come with vents that seem to be hidden away. They are located just under the rim of the lid and are not that large. Usually, they are just small gaps to let enough air flow in.
If you only have vents at the top, the wind can block the airflow and have the gas remain trapped inside. It is best to add a couple of extra vents lower down, near the bottom of the box, to make sure the gas always has an escape route.
But you should do your own research and check to see if there are any government regulations stating how these battery boxes should be constructed and vented. From the DIY options we have seen, there does not seem to be any real regulations for anyone to follow.
RV Dual Battery Box Vented
The best battery boxes will either have holes pre-made or a tube long enough to make sure the box is vented to the outside of your RV or trailer. This is the same for dual battery boxes. The only difference in the dual over the single version is that it should have more vent holes or hoses.
While they will have top vent holes, these are not always enough especially when you have double the charging and double the gas creation. You need to check out these boxes to make sure there are enough vent holes and that they are in a position where they won’t get clogged.
Many dual vent box designs easily hold both batteries. The key to having a dual system is to make sure the batteries cannot touch each other if something happens. if they do, an arc could occur and you would be looking for either new batteries or new electrical equipment.
The dual boxes would need to have dividers inside to make sure that arc never takes place. Nothing is stopping you from using 2 individual battery boxes side by side. This may be handier and easier to use.
Century Plastics Battery Box
This is just one brand of battery boxes you can buy for your RV or trailer. They come with a removable lid and on diagonal corners, 2 vent and cable holes each. made from polyethylene these boxes are supposed to be light, flexible, and strong.
The polyethylene material is said to be capable of holding any acid spills that may take place during your journeys. Plus, rough terrain is not a problem as the construction material is strong enough to hold your batteries where they are supposed to be.
Other features include being corrosion and leakproof and the plastic material is about 3/16ths of an inch thick. They are also designed in a way that allows stacking and their approx. dimensions are 21 by 12 by 12 inches. The lid makes them slightly larger.
One drawback, of course, is their cost. You can expect to pay just under $100 per box. Another will be that the company does not supply any mounting hardware or methods to secure their boxes to your tongue or other battery holding location.
To make sure your battery brand will fit, make sure to measure accurately. Century made these boxes fit snugly while only providing minimal room for movement.
Water in Battery Box
This is not really a health hazard or a dangerous situation for you. Too much water in the battery box can be harmful to your battery and those boxes should be drained. However, most battery boxes are designed to contain any acid leaks.
This presents a problem. How to get rid of the water and still protect against acid leaks. The only way to do that is to put a maintenance-free battery inside the box and then drill holes in the bottom of the box to let the water drain out.
Another solution is to cut down on the number of holes in your battery box has. Water will find its way in somehow and the way to keep water out is to block its entry points. This presents a venting problem if you are not careful.
The key is to make sure you have blocked any water entry routes without blocking the vents. Battery boxes are designed to keep acid inside and you have a tricky situation here as keeping acid inside means keeping water inside as well.
It also means keeping the hydrogen gas inside. You need to devise a system that services all three issues at the same time. That may not be an easy thing to do. You may just have to regularly check your battery box and simply dump it when you see water inside.
Where To Find a New Battery Box
Amazon has a large selection of these items and they should be reasonably priced. Depending on the features and design, their boxes ranged in cost from $10 up to $100. Next, you can try Camping World or some other RV parts and accessory outlets.
They advertise that they have these boxes in stock and their selection is reasonably priced. They also have extra vent hoses and couplings on sale in case you need to pick up some backups.
E-trailer is on the high side when it comes to the price of their battery box selection but check them out anyway. We recommend that you go to the big box stores instead of buying online in this case.
You will want to see these boxes in person to make sure they will meet your expectations and requirements.
Some Final Words
Wherever you purchase your battery boxes, make sure the vent holes are in the right location and there are enough of them. Since gases can get trapped inside, you want to have boxes with more holes than fewer ones. Plus, you want the construction material to be sturdy and strong in case anything unexpected happens
