Grommets to seal battery cables

[bdoyle]

I've got a Century Plastics battery box that is installed in the front storage bay of my fifth wheel. I have been looking for some kind of grommet that will fit around the cable to seal against the cutouts in the box. Been going thru lots of duct tape sealing this box and there has to be a better way.
Thanks, Brian

[valhalla360]

mike-s wrote:

valhalla360 wrote:
Have at it if you like but you are fixing a non-existent problem. If it was necessary to seal it, the box would have come that way.

If the box was designed to be externally vented, it would have been made to seal better.

:? Isn't that what I said?

[mike-s]

valhalla360 wrote:
Have at it if you like but you are fixing a non-existent problem. If it was necessary to seal it, the box would have come that way.

If the box was designed to be externally vented, it would have been made to seal better.

[valhalla360]

bdoyle wrote:
The box is vented to the outside with two 1.5 - 2 inch dia hoses. An inverter / charger is also mounted in that storage cabinet. I really don't want hydrogen gas building up in the compartment. Since the box does not seal by design, I normally wrap a few turns of duct tape around the box. I do have a watering kit installed so I really don't have to access to batteries that often. I just thought there might be a better way of doing this. It is not a round hole in the box, it is more of a slot maybe 1 inch wide 1 3/4 deep with a flat on the top. Just wondering if some one had come across something that was made for that box.

Have at it if you like but you are fixing a non-existent problem. If it was necessary to seal it, the box would have come that way.

[MEXICOWANDERER]

You'll find these on eBay. They seal. They grip the cord. They have enough material to fit a quarter inch thick wall and they are corrosion proof. Been using them for years. They are effective strain reliefs. I just bought some for the new 130 amp Meanwell charger.

[bdoyle]

There is no strain on the cables as everything is pretty much tied down. I recently bought a repo mobile home to fix up and retire in. They have some sealant that they goop around pipes and wires that is almost impossible to cut thru. I could probably 'cast' some of this around that cables.
Thinking about casting I used to make molds to cast partholding fixtures with devcon mix. I could give my kid a drawing and have her 3d print a mold up. I was always using a durometer 90 rubber but thet make softer.
I was also considering the bulkhead fittings but then I would have to seal up the other slots. I just haven't given much time to a good solution.

[mike-s]

bdoyle wrote:
Just wondering if some one had come across something that was made for that box.

I'd explore the weatherstripping section at your local big box store. You may be able to find something which can be glued along the inside edge of the top, so that it seals when the lid is pulled tight by the hold down straps. That would eliminate the need for duct tape. It also shouldn't be hard to find some closed-cell foam which can go around the cables and fill that gap. Maybe cut a chunk off one of those floating pool "noodles."

[DrewE]

One possible solution would be to seal the wire insulation to the hole (or a perforated plate over the hole with more closely sized holes) with some sort of caulking/sealant. So long as there isn't significant strain on the wires causing them to move this should hold just fine.

[myredracer]

Could use a bulkhead battery connector as used on sealed battery boxes. Can use a boot over the terminal on end of wire like in 2nd photo if needed. I used these on a sealed battery box with lead acid battery in a previous TT. An AGM battery would be a good upgrade but should still be vented as they can vent gas if they get overcharged.

MTS Products makes an inexpensive sealed battery box for RVs. I was in the parts section of an RV dealer once and they had a stack of used ones for sale at the back for $5. Got a couple of them that looked like new. These boxes are used in FWs. Has a built-in gasket and a flange on top and bottom.

[bdoyle]

The box is vented to the outside with two 1.5 - 2 inch dia hoses. An inverter / charger is also mounted in that storage cabinet. I really don't want hydrogen gas building up in the compartment. Since the box does not seal by design, I normally wrap a few turns of duct tape around the box. I do have a watering kit installed so I really don't have to access to batteries that often. I just thought there might be a better way of doing this. It is not a round hole in the box, it is more of a slot maybe 1 inch wide 1 3/4 deep with a flat on the top. Just wondering if some one had come across something that was made for that box.

[valhalla360]

prichardson wrote:
Why do you feel that it needs to be sealed that well? Unless you are using an AGM battery the box needs to be vented. If an AGM or other sealed battery there is no need for a tightly sealed container.

X2 What are you trying to accomplish by sealing the box?

[prichardson]

Why do you feel that it needs to be sealed that well? Unless you are using an AGM battery the box needs to be vented. If an AGM or other sealed battery there is no need for a tightly sealed container.

[Sam_Spade]

folivier wrote:
Does it need to be waterproof?

I was wondering that too.
Battery boxes usually are not completely sealed.....by design.

[SidecarFlip]

Dell electronics or Digikey

[Jim]

Along with Ace or TrueValue, I know Harbor Freight carries kits of grommets and O rings.