Community Forums

MFortie · 07-03-2012, 02:38 PM

UPDATE:

Removed the house batteries and cables last night and was able to start the coach via the chassis set. We moved it onto it's 'pad' and plugged in -- we have 120V power and limited 12v power. The water heater & frig igniters work; the step works, but the jacks won't fully deploy and the slideout won't move. Must not be enough juice from the converter to run those systems.

The FD had cut the ground cable and removed it from the house bank -- I think it connected to the chassis bank ground post and I'd like to throw my extra deep cycle in just to run the jacks.

Can anyone confirm the ground from the house set should connect to the chassis set? The positive side was connected to a positive bus bar on the bulkhead.

Thanks,

Mark

EDIT: Just followed EM's link and it has the wiring schematic for the batteries banks. Thanks Mike! BTW, what type of engineer are you?

Pollo man · 07-03-2012, 05:29 PM

Your right. The house neg connects to the chassis neg.

If your in need of Heart 458 inverter repair, Fuge Electronics in Ocean Beach (San Diego) just fixed ours with new board.

Also, we have a set of wiring diagrams if you need them.

Gary
Orange, CA

Birddog Pilot · 07-04-2012, 04:37 PM

This at least the third report, that I can recall in the last couple years, of AGM batteries on fire. Is there a problem here?

clyon51 · 07-04-2012, 04:59 PM

I doubt I would ever buy AGMs unless I had to put them in a living space. According to the OP, the fire was caused by a metal holding bar grounding out the positive post. It's beyond me why a mfg would use any battery holding devise that's grounded and would have any possibilty of contacting a post

Rich and Cork · 07-04-2012, 05:49 PM

I would also do a search on this site for a very neat rearrangement of battery cables by a member some years ago. There may even be a couple of threads. Maybe someone else has them bookmarked and can post them.

OldForester · 07-04-2012, 08:13 PM

When we installed our 8 AGMs we were concerned about the battery hold down straps potentially contacting the positive post of the batteries. We ran the hold down straps through automotive heater hose and it did a good job of insulating the straps from the positive posts.

MFortie · 07-05-2012, 10:00 AM

Should insurance pony up and replace the AGMs, I'm going scallop the hold down bar to provide clearance from the posts. I'll also look into some insulating material, like Starboard, either under the bars or to replace them.

I also wonder why the mfgr's don't use some type of battery box?

Like this:

Ramblin · 07-05-2012, 11:19 AM

Quote:

Originally Posted by MFortie

...
I also wonder why the mfgr's don't use some type of battery box?

Like this:

Because, while that may be the BEST solution, it's not the most econimical.

EngineerMike · 07-05-2012, 12:44 PM

Most AGMs have pretty clean, level tops. The flat bar used for most moho batt holddowns isn't ideal to actually hold them from vibrating sideways vs the bar. Flooded batts have the cell cap topography to stop some of that. But I've seen flat bar shorting out against the posts on flooded batt's also.
Best thing is to go to non-conductive holddown material. I used 175# zip ties on mine and took the bars/threaded rods out. Not much in the way, clean looking, come in 36" to 72" lengths. I used the round holes in the tray floor and one short stud w/fender washer in the rear bulkhead for anchor points, and tied the group of 4 batt's together as well.

Others have made flatbar of thick poly cutting board material (TAP Plastics, etc.) with great success. Some took flatbar to a shop that sprayed heavy duty non-conductive coating like Rhino Liner, and got their flatbar coated. You could wrap flat bar w/2-3 thicknesses of X-treme Tape for 2" or so past each hot post (4" min length covering bar in case anything moves).

Anything to avoid shorting a hot post to ground, which will give you a bad day.

takepride · 07-06-2012, 11:31 PM

Cans of Rhino Liner are now available at Home Depot. Good shortcut.

Renipladlo · 07-07-2012, 12:57 AM

FWIW - We had AGM's installed last November, when I was putting the cables back, it was determined to NOT use the hold down studs or bars, (studs are in place but the bars were not used but saved, as I have a theory as to use them safely) as they would short out if the batteries moved. It was also noted that the inside (to the center of the coach) and rear (to the rear of the coach) (so now we are talking about the left rear battery post) could move and short against the metal bulkhead possibly, so I put in a piece of very thick cardboard to keep the battery spaced away from that bulkhead. Once we get the coach back (someday in the distant future), I plan on getting some ¼ to 3/8" thick rubber matting, and permanently put it in that location so the batteries could never move and short out on that bulkhead.

Please Note All - We all should change our Smoke Detectors to this model, unless you already have. The "Kiddie Dual Sensor, Battery Operated Photoelectirc/Ionization Smoke Alarm Model PI-9000, Part Number 442007. Mac Sells them as well. They can be purchased other places as well, Lows, HD, Ace Hardware, Amazon, etc.

FWIW#2 - http://macthefireguy.com/products - Buy several of these and keep one in the battery compartment, one in the bedroom, one in the drivers area, and one in the kitchen. He put on a seminar at one of our Rallies at Quartzsite, and the foam extinguishers he sells are 1000% better than any dry powder one sold at Lowes, etc. I use the old powder one in the car, in case it catches fire. Remember to beat on them a little every month or so to keep the powder stirred up. I think at the seminar, he sold one 10# foam, and 3 of the smaller foam ones as a special, it may be on the website.

FWIW#3 - Had it been mine, I would have watched it burn down to the frame rails. As a routine, when we camp, I tell my neighbor, if it burns don’t call the FD for 15 minutes so it’s totaled.

bcbowers · 07-07-2012, 11:03 AM

Monty,

After experiencing a battery compartment fire that took almost a full year to repair by a local RV dealer, and the insurance company paying out $33K, your "FWIW#3" is advice I will be following IF it happens again. I carry 2 - 35 lb. fire extinguishers but will have a tough time deciding to use them unless the fire is VERY small. My coach was returned to "normal" but I do NOT want to go through that again!

Interestingly, the house batteries were AGM's and installed by a "small time" battery shop by the previous owner. One of the cables appeared to have been laying down on the hold-down bracket and eventually shorted. The new batteries are wet cells and the new cables have large insulators between posts well suspended above the hold-down brackets. Still, you can never be 100% sure that a battery fire won't happen!?

Renipladlo · 07-07-2012, 12:13 PM

I open up that compartment at least weekly to make sure vibration, etc, has not caused those cables to lay down on the posts, etc. I am working on a solution to the hold down brackets, but don't know if it will work and so I need the coach back to prefect it, then we have the 95% solution, I don't think there is anything we can do for the other 5% part. No system is foolproof I don't believe. The compartment should have been engineered with more room and space around the batteries, but we have to live with what we got.

EngineerMike · 07-07-2012, 05:00 PM

Pretty sure that a bank of batteries, alone in a 10' x 10' x 10' room and shorting directly to ground, would start a fire. Maybe the 10' ceiling and walls maybe 4' laterally wouldn't catch fire. But I'd hate to have to haul that big battery box around; I'd be tempted to store stuff in there for sure.
Dead shorts = BAD.
Just take the time to hold them down w/out possibility of dead short.