NOMADICISTA

I'm looking for input from folks who have successfully kept flooded batteries inside the living space of a bus or house truck. Our former transit bus has no below floor luggage bays. My current house batteries are a pair of 8D size gel cells that hang below the driver's compartment because I had space there.

I'll soon buy four or eight flooded batteries to go with a new solar charging system. I have room for them inside the coach where it will be easier to maintain optimal battery conditions, but I'm concerned about outgassing.

Is it possible to do this safely? I'm thinking of building a plywood box, lined with fiberglass reinforced plastic sheet, tight fitting lid, vented to outside with PVC pipe. Could this work? Do you have a better idea?

AGM batteries do not look like a viable option at this time.

Thanks in advance,

Jim in Western North Carolina

Hi Jim ~ I have done the same thing in several coaches I have lived in and never had any problems. Be sure to seal the box well from the living quarters and vent it to the outside world. I had some of my box lids held down with sheet rock screws...that means unscrewing the lid to service batteries..not to hard with a cordless drill. I would use some type of rubber or something on the lid to make a good seal when you screw down.

Bob...you just answered another question for me. Thanks!

ezrablu wrote: Bob...you just answered another question for me. Thanks!

Was it about screwing? you know...the lid

My battery compartment in the trailer is sealed galvanized sheet metal box, sitting right under the sofa bed. Vents with a vented door outside. Anything less than that sounds like kind of a bad idea. I would worry about it.

Would buying half as many at twice the price let you ease into the AGM??

And Bob, you are sooooo naughty!

Remember that Hydrogen is one of the most difficult elements to contain. If you vent the battery enclosure to the exterior and seal it well (and not necessariliy fanatically) from the inside, you'll be fine. This assumes that you aren't boiling tbe bejezus out of your bank during an equalizing charge. In that case, extra ventillation (and caution) is called for.

Just make sure the vent is at the ~top~ of the compartment, and you won't get a significant buildup of H to create a flammable mixture. Hydrogen is lighter than air (duh).

More you should be worried about hydrogen sulfide gas buildup, and the attendant corrosion it causes. H²S is poisonous as well, so make sure it has a way to dissapate and keep it out of your living space.

I love this forum. It never fails to help me think.

What I'm thinking now is that maybe AGM batteries are the way to go. I think I could live with lower capacity in exchange for greater safety. Flooded batteries seem to have jumped in price anyway. (I've been looking at the Trojan L-16.) AND I'll save money and time not having to build battery boxes.

I'm considering a bank of Concorde Sun Xtender PVX-2240T 6v batteries. I think we could swing four of those now and add four more later. I'll have a good backup option (thanks in part to this forum), so I think we'll have no trouble surviving cloudy weather. Looks like I can buy these for $300/ea including shipping.

If anyone has AGM advice or recommendations, I'd love to hear it.

Jim in Western North Carolina

Hi Jim,

It sounds like you have a good start on your bus, do you have any photos of it? I would to see it.

Chuck

AGM batteries still need to be in a vented enclosure. Although they don't emit hydrogen in the same levels as flooded, they do emit a tiny amount ~and~ they have pressure seals that will vent to the exterior if they are overcharged or otherwise build up pressure. If they once do this, they are toasted, because there is no way to put replacement water/electrolyte back into the cell.

AGMs can be discharged and recharged very rapidly. This is an advantage when you need peak-power grunt to start big loads on an inverter, etc. In every case, an AGM will outperform flooded in ampere supply. The ability to charge quickly is of benefit when a lot of current is available for a short time, as in charging from a generator. Charge control is critical, overcharging them results in damage.

They have a very low self-discharge rate when left sitting around fully charged. They suffer badly if left sitting around in a discharged condition, as they tend to sulfate quickly. This is a problem as soft sulfur deposits that could easily be removed by an EQ charge in a flooded cell can't be removed from an AGM because you can't push the voltage up to the gassing point and hold it there for a few hours. The sulfur then hardens and you lose capacity in the battery. You should absolutely have a means of bringing AGM battery banks up to full charge at least every few days, as operating them in a partial-discharge state will result in poor service life.

In short, if you are a "battery abuser", save your money and get floodeds, they suffer such neglect more gracefully. If you need batteries that can sit around all winter without a top-up charge (disconnected from loads, of course), the AGMs are your brand.

Hello Chuck,

The Flex is too ugly to show right now. I've had it almost ten years and used it a good bit for recreation and some travel with our Bluegrass band. Wife and I are in the process of going full-time, and the Flex will be a transition to something better. Likely a 40' MCI.

Most of the "systems" in the bus are in pretty good shape, except that it never had solar or backup charging. We usually stayed in places with shore power or carried a small Honda generator to recharge the 8d gell cells. The bus always leaked, and the interior was never satisfactory. I have most of the interior stripped and the worst roof leak fixed. That gives me a chance to repair some exterior panels where Sika Flex 252 failed. Some of these I'm welding and some are being rebonded with 3M 5200.

I'm almost through stripping the interior. Then, as soon as the shell is tight and dry, I'll begin rebuilding the interior from scratch. When I'm not so embarrassed about the exterior condition, I'll make some photos.

I'm inspired in this rebuild by my motorhome hero, Rob Gray and his Wothehellizat. Thanks to Sharkey for posting that link on this site.

Jim

That's why you want to show pictures now...it's the process and progress you are showing. Going from here to there. Nothing to be embarrassed about at all. (Did you see my bus? If embarrassment were an issue, it should apply here.)

Not only that, showing pictures of the process can be very inspiring for someone such as myself who is about to embark on my own very first bus conversion.

Plus, you can point out things in the pictures that may be important for others to watch out for, and we can actually see what you are describing rather than trying to imagine it.

Allright already. I'll take some pictures today and post them sometime this weekend. I'll put them in the Bus Barn forum since they'll have little to do with solar power.

At least I'll be far enough away that I won't have to listen to the peals of laughter. We've had the bus for nearly ten years, and it's been ugly the entire time. Just happens that it's uglier than usual right now. I won't be able to post pictures of the bus in its transit livery or earlier stages of construction because most of our possessions are in storage.

I've decided that posting the photos will work to my advantage. Knowing that others can see the sorry state of things should help keep me motivated to plug away at the project. The fact that we need a place to live would seem to be enough in that department, but every bit of encouragement helps.

I'm distracted from the bus right now by a bathroom remodel in the ancient farm house we've rented. I've discovered that the entire floor, including the joists, is too rotten to use. Nothing like wallowing in a moldy/muddy crawl space to make one dream about how nice it will be to get to live in the ugly bus. But then, she won't be ugly forever.

Photos coming soon.

Jim in Western North Carolina

YAY!!!

Nice