Battery Fire and Questions

[MFortie]

Hi All,


Had some issues with the battery bank yesterday and am soliciting info from our knowledgeable members. Questions first for those that aren’t inclined to read the saga…


Coach: 2000 36’ mid-door, single slide. SN# 72230

1. Are the house batteries required in any way for the shore power circuit? (Can the batteries be completely removed and the coach plugged into shore power and function correctly…)
2. Can the coach be driven (using the chassis batteries to start) safely without have the house batteries installed?
3. If the house batteries are removed, are there any other disconnections or changes that should be made to the electrical system?
4. Does anyone have a wiring diagram for our year coach?

Back Story:
My wife and I bought a piece of horse property east of San Diego with a couple of fixer-upper houses on the property (5.5 acres).


We’ve been staying in the coach on weekends while we worked on the place and had plans to move into the coach full time after our family vacation in late June.


We went to the Sierra’s the last week in June towing our Jeep and spent the week doing some fishing, offroading, relaxing, etc. No issues up and back – everything worked well including the new US Gear Unified Brake system we just had installed (we’ve had to do our brakes/calipers twice on this coach and are overly cautious about putting any extra load on the braking system!)


Came home Saturday; Sunday (7/1) was to be our ‘official’ move date to the new property (we still have our existing home that our daughter and her family are renting from us.) Headed up late yesterday and about ten miles from our new home, a fellow flagged me down on the freeway and told me something was burning (he could see flames) in the back. Pulled over and went back and saw melted plastic dripping onto the ground (and smoke) from the battery compartment.


Opened the access door and two of the AGM batteries were in flame (closest to the door). I grabbed the fire extinguisher and put out the fire (or so I thought) and called my wife to tell her the problem (she was about a half hour behind me in a truck pulling a trailer loaded with horse corrals). I also called our insurance company to arrange for a tow and while on the phone, I started smelling something burning again. Apparently the short wasn’t quite finished and the batteries lit up again. Of course I had already exhausted my fire extinguisher on the first go round.


I had the roadside assistance folks on the phone and they called the fire department for me. After I hung up, I thought I’d shut off the two master switches and see what that did and sure enough, the glowing orange threaded rod that holds the hold down angle iron in place started to cool off and the fire put itself out. About then a USDF truck pulled up (we were in the Cleveland NF) and offered to stick around ‘til the FD showed up – he had a fire extinguisher on board as well.


The FD showed up shortly after and added some foam retardant to my efforts to help cool everything down. Once they determined the coach was safe and out of danger, they made their report and went on to the next call. They determined the angle iron hold down had shorted out on one of the battery posts…


We had the coach towed to our new place, but the driver wasn’t able to drop it at our prepared ‘RV site’ (power, water, sewer). We spent the night leaning to the right and since I sleep on the left, my poor wife had to put up with me rolling ‘downhill’ and snuggled up with her!


My hope is to be able to pull the house batteries out, start the coach on the chassis batteries and move it onto the ‘pad’. Once there, I’d like to plug it in so we can have power. We won’t be going anywhere for about six months anyway as we have a time limit on completing our rehabs (FHA Rehabilitation Loan), so I should have plenty of time to repair the coach (if insurance won’t cover the repairs.)


We were very fortunate not to lose the whole coach and the damage appears to be isolated to the battery compartment and the actually compartment suffered no burn damage at all! I’m concerned more of the electrical system might be damaged/compromised, so I want to evaluate the system thoroughly.


My wife and I do MEPT work (engineering firm that she’s part owner of) and are familiar with schematics (we call them ‘single lines’), but I don’t have anything from the factory to work with.


Thanks in advance for reading and any info offered!

[RickO]

Sorry to hear about your troubles but glad it wasn't any worse. As you know it sure could have been.

I'm sure some of our experts will be along shortly (no pun intended) to offer advice but IMO:

1) I believe you do need the 12v house batteries to even get shore power in to your coach. At least that's how my Winnie operates.

2) I don't think you should have a problem operating the chassis/moving the coach without house batteries installed.

3) I think just making sure your house battery disconnect switch is thrown is all you should need to remove the batteries.

Best of luck.

Rick

[JimM68]

If you need the batteries or not depends on your charger/converter, check thier website or csall them asap...

Be carfeul with this stuff, those batteries can deliver hundreds of amps, lots of power, lots of heat.

If the problem was caused by the holdowns shorting out, and the battery cases were not compromised, you might still have good batteries.

get a new extinguisher asap!!!!

[RickO]

Originally Posted by JimM68

get a new extinguisher asap!!!!

... or two... or three!

Rick

[MFortie]

Originally Posted by JimM68

If you need the batteries or not depends on your charger/converter, check thier website or csall them asap...

Be carfeul with this stuff, those batteries can deliver hundreds of amps, lots of power, lots of heat.

If the problem was caused by the holdowns shorting out, and the battery cases were not compromised, you might still have good batteries.

get a new extinguisher asap!!!!

Battery cases are slag on the side of the freeway; they were aflame and dripping melted plastic out of the compartment.

At least I know what the AGM plates look like now!

And yes, new extinguishers are on today's shopping list (note I used the plural...)

[Ramblin]

Originally Posted by MFortie

And yes, new extinguishers are on today's shopping list (note I used the plural...)

I bought four of THESE for my coach. One in bedroom closet, one under kitchen sink, one in driver side bay, one in passenger side bay.

[wa8yxm]

On a 2000 I believe you can safely pull the batteries and plug in.. There are some limits though. . Will discuss in a bit,

As for operating the Truck part of the motor home, No problems there at all with one slight exception.. That is if you pull a bonehead move like leaving your headlights on while you stop for dinner, Sans the house battery, no built in "Jump Start".

Now, Some issues.. First: If you remove the batteries make sure you secure the cable ends, Epically the positive cable, Tape it off well, (Personallyh I'd slip a bit o PVC pipe or vinyl tubing over the end then tape it off) Insure those wires do not short.

Now, several things may not work without batteries, Steps and slides are the #2 and #2, Jacks are down the list, and of course the generator may not start.

Finally... What caused the short in the first place.. You mentioned that when you killed the master switch, things cooled off, This suggests a high current short in the HOUSE SIDE of the disconnect switch.. And that,, Will destroy your converter.

So find the cause and correct it first.

Two comments on the fire extinguisher.

In addition to the toy Damon gave me I have a 25 pound powder bottle from a local supplier and two foam canisters from Mack The Fire Guy, Google Mack The Fire Guy and order new extinguishers from him... What I know about fire science is ... Little.

Mac.. Well, let me put it this way, What he does not know..Is not much.

[Dr4Film]

Your Inverter/Converter will determine whether you can run 12 VDC items without having your house batteries installed. I have the Xantrex Trace RV-2012 and when I had ALL of my batteries removed to clean and repaint the battery trays, I had use of all electrical systems in the coach.

If you are concerned, just buy one 12 VDC deep cycle battery and hook it up. With shore power available 24/7 it should give you plenty to draw on.

When buying replacement FE's I would recommend using an aqueous film fire extinguisher type versus the old style chemical ones. I bought mine from Mac The Fire Guy. Link beloiw.

My Business - Products

Dr4Film ----- Richard

[clyon51]

The batteries are not required for 120vac shore power.

Depending on how your system is setup/wired, you could even have and use the entire 12vdc system. Even if you have the original converter/charger, which is probably 50amps. It's going to depend on your BCC.

Just make sure those batteries are isolated from the entire system, use the battery disconect switch (BDS) and I would also remove and insulate the POS batt terminal cable ends as some systems will charge the batts with the BDS engaged. You don't want any juice going to those cable ends and hitting any grounds.

Once this is done, plug into shore. Now check if you have 12vdc in the coach. If you do, I would say you're good to go. Your genny won't work, but I'm sure you're not worried about that.

No problem driving either with all the aforementioned done.

If you don't get 12vdc, you won't have power for CO2 and Propane detection and probably no frig or AC control.

[Old Trucker]

Originally Posted by MFortie

Hi All,


Had some issues with the battery bank yesterday and am soliciting info from our knowledgeable members. Questions first for those that aren’t inclined to read the saga…


Coach: 2000 36’ mid-door, single slide. SN# 72230

1. Are the house batteries required in any way for the shore power circuit? (Can the batteries be completely removed and the coach plugged into shore power and function correctly…)
2. Can the coach be driven (using the chassis batteries to start) safely without have the house batteries installed?
3. If the house batteries are removed, are there any other disconnections or changes that should be made to the electrical system?
4. Does anyone have a wiring diagram for our year coach?

Back Story:
My wife and I bought a piece of horse property east of San Diego with a couple of fixer-upper houses on the property (5.5 acres).


We’ve been staying in the coach on weekends while we worked on the place and had plans to move into the coach full time after our family vacation in late June.


We went to the Sierra’s the last week in June towing our Jeep and spent the week doing some fishing, offroading, relaxing, etc. No issues up and back – everything worked well including the new US Gear Unified Brake system we just had installed (we’ve had to do our brakes/calipers twice on this coach and are overly cautious about putting any extra load on the braking system!)


Came home Saturday; Sunday (7/1) was to be our ‘official’ move date to the new property (we still have our existing home that our daughter and her family are renting from us.) Headed up late yesterday and about ten miles from our new home, a fellow flagged me down on the freeway and told me something was burning (he could see flames) in the back. Pulled over and went back and saw melted plastic dripping onto the ground (and smoke) from the battery compartment.


Opened the access door and two of the AGM batteries were in flame (closest to the door). I grabbed the fire extinguisher and put out the fire (or so I thought) and called my wife to tell her the problem (she was about a half hour behind me in a truck pulling a trailer loaded with horse corrals). I also called our insurance company to arrange for a tow and while on the phone, I started smelling something burning again. Apparently the short wasn’t quite finished and the batteries lit up again. Of course I had already exhausted my fire extinguisher on the first go round.


I had the roadside assistance folks on the phone and they called the fire department for me. After I hung up, I thought I’d shut off the two master switches and see what that did and sure enough, the glowing orange threaded rod that holds the hold down angle iron in place started to cool off and the fire put itself out. About then a USDF truck pulled up (we were in the Cleveland NF) and offered to stick around ‘til the FD showed up – he had a fire extinguisher on board as well.


The FD showed up shortly after and added some foam retardant to my efforts to help cool everything down. Once they determined the coach was safe and out of danger, they made their report and went on to the next call. They determined the angle iron hold down had shorted out on one of the battery posts…


We had the coach towed to our new place, but the driver wasn’t able to drop it at our prepared ‘RV site’ (power, water, sewer). We spent the night leaning to the right and since I sleep on the left, my poor wife had to put up with me rolling ‘downhill’ and snuggled up with her!


My hope is to be able to pull the house batteries out, start the coach on the chassis batteries and move it onto the ‘pad’. Once there, I’d like to plug it in so we can have power. We won’t be going anywhere for about six months anyway as we have a time limit on completing our rehabs (FHA Rehabilitation Loan), so I should have plenty of time to repair the coach (if insurance won’t cover the repairs.)


We were very fortunate not to lose the whole coach and the damage appears to be isolated to the battery compartment and the actually compartment suffered no burn damage at all! I’m concerned more of the electrical system might be damaged/compromised, so I want to evaluate the system thoroughly.


My wife and I do MEPT work (engineering firm that she’s part owner of) and are familiar with schematics (we call them ‘single lines’), but I don’t have anything from the factory to work with.


Thanks in advance for reading and any info offered!

Hi Mfortie, so sorry to hear about your problem. I agree with those that said a battery is required and possible inverter/converter damage.

Wiring schematic; I have one for my 99 36 ft mid door serial # 72065. It is somewhat limited in info, but maybe being good engineers you can figure it out. If you send me an address, I would be happy to send you a copy. Old trucker. home email donjanettarobinson@hughes.net

[RickO]

Originally Posted by wa8yxm

Finally... What caused the short in the first place.. You mentioned that when you killed the master switch, things cooled off, This suggests a high current short in the HOUSE SIDE of the disconnect switch.. And that,, Will destroy your converter.

So find the cause and correct it first.

The OP indicated the cause of the short had been identified.

Originally Posted by MFortie

They determined the angle iron hold down had shorted out on one of the battery posts…


!

[MFortie]

Thanks all, I think I'll do a little testing and check out the inverter mfg. site as well...

Regards,

Mark

[EngineerMike]

Mark- see if this link is pretty close to your coach's battery wiring, this PDF file if dated 2001, so was current for 2002 coaches, but may be good for yours. There is one label I would argue is not quite optimal on that schematic- the inverter is shown w/2 "outputs" labelled Output1/To Main Panel, and Output2/To Sub Panel. I would call Output1 an Input (this is where the 30A brkr in the main panel feeds the inverter), and I would label it From Main Panel. Output2 is the 30A output to the black sub panel, and the 30A breaker in that panel is its "main" breaker feed to the sub panel.

As you can see from the linked PDF file, the inverter is direct wired thru the 300A fuse, so you have to remove or replace the house batteries. Should be able to use coach w/out house batteries, subject to safe'ing the hot cable ends. Start at the negative cables & disconnect from all batteries. Then take out positive cables. Once there is no positive cable to flop around & create a short, you should be safe to reconnect the neg cables, then plug in and turn on the inverter. Inverter now has no source to invert from, but you have 120V from your shore power till you are ready to recommission coach for the road.

Sounds like you had a hold down strap short to a + stud on one battery (based on red hot condition of hold down rod).

[Old Scout]

Just to clarify what EM described--you need to isolate and secure the positive cable from the inverter. Its a two-way street, you dont what the inverter drawing to invert 12v from the bats or trying to charge the bats from 120v. You can disable the charger but better safe to secure the pos cables...