Drain in battery case?

1tenor · 11-11-2021, 01:14 PM

I was puttering around in the barn today and pulled the battery out of its case and was surprised to see an inch or so of water in the bottom of the case. I'm not really sure how it got in there, but here's my question. Should I drill a small hole in the bottom of the case to keep it drained? I guess it does no real harm for the battery to sit in a water bath, but I think I'd rather it be dry. Any thoughts?

Canonman · 11-11-2021, 01:33 PM

Be careful! That might be acid that has boiled off from the battery.
I did add some 1/4" drain holes to our battery cases when we had our bumper pull. Not a good idea if the batteries are in a cargo area as they are in a 5th wheel.

**JRTJH** · 11-11-2021, 02:53 PM

All battery boxes that have "vented lids" will allow air in as well as allow venting of battery vaporization out of the box...

When a battery is being charged, it is warmer than the space around it (inside of the battery box) and any humidity moving from the "cooler, more dense air outside the box" to the "warmer air that can hold more moisture" that's around the battery, will set up a "water vapor migration into the battery box"... Over a time frame of weeks or months, that "water vapor migration" can lead to the battery sitting in a pool of water inside the battery box.

Two ways to handle it:

1. Turn the battery box upside down and pour it out occasionally

2. Drill drain holes in the box to allow the water to drain.

If you do #1, make sure it's really water that you're pouring out of the box.

If you do #2, make sure that anything draining from the box is water. If it's not, you stand a good chance of "dissolving your steel battery rack on a travel trailer" or "eating away the metal grid under the battery boxes in your fifth wheel".....

In short, it's common in a high humidity area, to have some water accumulate around a battery in a vented battery box. How much depends as much on how much the battery is being charged (more trailer use means increased charging) and how "wet" the air around the trailer is. Failing to dump the box regularly can lead to a "submerged battery" if it goes long enough...

**flybouy** · 11-11-2021, 03:48 PM

Drill a couple of 1/4" holes in the bottom of the box if it sets outside and don't worry about it. Do be concerned with the proper use and maintenance of the battery itself. Batteries are not a "install and forget" item and "maintenance free" batteries are like "flushable wipes". If you beleive in that hype then keep lots of cash handy to pay for the future damages.

rhagfo · 11-11-2021, 03:52 PM

I added a second battery to our 5th wheel, and the vented case had a drain hole in the bottom, the same configuration as the top to attach the vent hose.

Canonman · 11-11-2021, 04:34 PM

Quote:

Originally Posted by rhagfo

I added a second battery to our 5th wheel, and the vented case had a drain hole in the bottom, the same configuration as the top to attach the vent hose.

Our Cougar is set up that way as well. But that large hole in the bottom really isn't a drain. It provides for air exchange to insure venting of the battery gasses that could make their way into the interior of the trailer.

**JRTJH** · 11-11-2021, 05:21 PM

Actually it's an "engineering marvel" that not only serves as a battery box with a bottom drain and a bottom vent, but it's also two identical halves that when set side by side, can become either a top or a bottom.... But, the "engineering marvel" part falls short when you consider that there's 10 nuts and bolts that hold it together and only one entrance/one exit for pos/neg battery cables, on opposite ends of the box which makes it difficult to extremely difficult to check battery acid levels on a regular basis, or to connect more than one battery to a circuit, if that series or parallel connection requires more than one battery cable to enter/exit the battery case.

T'was a good design that didn't/doesn't work well in practical use when it comes to maintaining batteries......

Canonman · 11-11-2021, 05:43 PM

That's why I chose this Camco Double battery box.
https://www.campingworld.com/camco-d...E&gclsrc=aw.ds

The slip fit cover is adequate for our configuration inside the front cargo box in the Cougar. If I were to use this type box on the trailer tongue, I wouldn't use more than 4 screws to hold the lid on.

Javi · 11-11-2021, 05:53 PM

Quote:

Originally Posted by JRTJH

Actually it's an "engineering marvel" that not only serves as a battery box with a bottom drain and a bottom vent, but it's also two identical halves that when set side by side, can become either a top or a bottom.... But, the "engineering marvel" part falls short when you consider that there's 10 nuts and bolts that hold it together and only one entrance/one exit for pos/neg battery cables, on opposite ends of the box which makes it difficult to extremely difficult to check battery acid levels on a regular basis, or to connect more than one battery to a circuit, if that series or parallel connection requires more than one battery cable to enter/exit the battery case.

T'was a good design that didn't/doesn't work well in practical use when it comes to maintaining batteries......

I have a similar box without the extra drain, what a pain in the butt... I left all but two of the screws out but to raise the top high enough to actually check the acid you have to disconnect the battery cables from inside the top.

Did I say pain in the butt...

**JRTJH** · 11-11-2021, 05:55 PM

I went a slightly different route with a Century Plastic dual GC2 box. They make a "side by side dual box" a "end to end dual box" and even a "4 battery GC2 box"...

At the time I needed a "golf cart battery box" Century had about the only "functional box that could be vented and sealed" on the market. At least the only one with a reasonable price tag..... Now, there are a lot of other choices, many even "nicer and more functional" than the Century boxes.

1tenor · 11-15-2021, 09:09 PM

Thank you. That makes a lot of sense. Very humid here. I'm sure that it was condensation. I'll keep a closer eye on it and perhaps drill a hole in the bottom of the case where it will drop straight to the ground.

DDuncan51 · 11-21-2021, 09:51 AM

How to tell if it's water or acid: Dump a little coca-cola in it. You'll know.

dooby · 11-21-2021, 11:06 AM

Quote:

Originally Posted by 1tenor

I was puttering around in the barn today and pulled the battery out of its case and was surprised to see an inch or so of water in the bottom of the case. I'm not really sure how it got in there, but here's my question. Should I drill a small hole in the bottom of the case to keep it drained? I guess it does no real harm for the battery to sit in a water bath, but I think I'd rather it be dry. Any thoughts?

I've been there with my first TT. I drilled a 1/4 inch drain hole in each corner of the battery box. I didn't need to do it with my new TT as it was either done by the manufacturer of the dealer

Folkie · 11-21-2021, 08:10 PM

I had the same issue with my TT, but it was definitely from rain coming in the cover vent ports. My solution was to silicone caulk the vents. There is still ample ventilation through the cover's gaps for electrical cables. Haven't had any condensation accumulation using this approach with my last two campers.

Bamabox · 11-22-2021, 08:34 AM

Quote:

Originally Posted by Folkie

I had the same issue with my TT, but it was definitely from rain coming in the cover vent ports. My solution was to silicone caulk the vents. There is still ample ventilation through the cover's gaps for electrical cables. Haven't had any condensation accumulation using this approach with my last two campers.

That’s absolutely true. I wish I had been smart enough to think of that. So instead I drilled the 1/4” holes in the bottoms VERY CAREFULLY. Fixed the problem, but I still might caulk the vents. The way the rain comes off the front cap of the camper, it drops right on the battery cases. And like you said, those cases are hardly airtight.

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