House battery fire

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

aribb

Active member
Joined
Jun 19, 2011
Posts
38
My son-in-law and daughter borrowed our 2011 Winnebago Tour this weekend to go see the Michigan football game. A little while ago he  called and said there was smoke coming from the center of the motor home. Long story short, the house batteries caught on fire. The fire was put out, the fire department removed all six batteries, 5 of which at burnt to a small pile of plastic and lead. After everyone had calmed down, I told him to turn the chassis switch back on and try to start it which it did.

Two questions, is there any reason they can't drive it home tonight?

Also, the local motor home repair place just replaced all six AGM batteries about a week ago. Obviously doesn't seem like a coincidence. Possible causes??? Batteries hooked back up incorrectly? Defective battery shorted out? What are my talking points with the service manager on Monday morning?

Thank you.


Edit by staff - changed message icon to topic solved
 
Wow!  Lucky the entire rig didn't burn down.  Yes, I think much more than a coindence but unless someone took a bunch of pictures or did a forensic analysis you have zero leverage with the shop. I would mention the situation to the shop owner and see where the conversation goes.

With no more danger from fire I think it's okay to drive.
 
I'd make sure all cables and wires in the burned area are insulated from shorting out while bouncing down the road. Especially if your engine alternator charges those batteries like most do. Also if the generator will be run for roof air, wait, Michigan, if the generator will be run for any reason.... make sure that whatever charges those batteries doesn't create a problem.

Most likely the battery install was the problem. As John says though, proving it will be tough. As a gesture of goodwill the shop should be providing some of the labor or material to make it right. If they don't, I'd make a big deal of letting them know they would no longer be getting my business.

Ken
 
Thanks guys. I like the idea of making sure all the cables that went to the batteries are well taped and protected for the trip home. I'll make sure they don't run the generator. No need for AC. Although a beautiful fall day, it's only in the 60's

Yes, I'm very thankful it didn't burn down the motor home. It's parked in a lumber yard about a block from the stadium of 110,000 people. Would have made the news tonight for sure. Lots of blessings.

The MH repair shop is a reputable place. I'm sure they will stand behind it. About $2,000 in batteries! Fire chief suggested one battery hooked up backwards??

Anyway, looks like Michigan will win so not a bad day after all! Go Blue.

Thanks again.
 
John,
The new batteries had only been in for a little over a week. This was the first trip since having them installed. Take a look at the pics they sent me.... Melted the battery.
It took a little while but over the phone we figured out how to get the electric awning in and the bed up so they could put the slides in. They are ready to hit the road for about a 120 mile trip home once the traffic clears in a hour or so.
I'm just very happy it didn't happen in the middle of the night. Many blessings!

So don't let your kids borrow the motor home!! Just kidding
 

Attachments

  • image.jpeg
    image.jpeg
    156.5 KB · Views: 179
  • image.jpeg
    image.jpeg
    132.5 KB · Views: 163
First, really glad to hear the damage was contained to the battery compartment. We have the same AGM six-battery setup in our 2011 42QD, and I can't see how it could have gone a week with a battery hooked up backwards. I'd also be curious to know if any of the 12 volt house systems were working during that week.

The way Winnebago designed that battery compartment, the tops of the batteries sit very close to the bottom of the battery compartment cover, and the bottom of the cover is edged by metal. I'm always very careful when I take it off and put it back on to avoid shorting out the terminals. I'm wondering if there were some terminal-clearance issues with the new batteries. Just a thought.

Kev
 
Kevin Means said:
The way Winnebago designed that battery compartment, the tops of the batteries sit very close to the bottom of the battery compartment cover, and the bottom of the cover is edged by metal. I'm always very careful when I take it off and put it back on to avoid shorting out the terminals. I'm wondering if there were some terminal-clearance issues with the new batteries. Just a thought.

Kev

Kev, how about putting a thin sheet of rubber over the terminals something like rubber from a old inner tube.
 
It might be possible the battery suffered an internal short, which with all the available amperage could have resulted in the fire.
 
Kevin Means said:
First, really glad to hear the damage was contained to the battery compartment. We have the same AGM six-battery setup in our 2011 42QD, and I can't see how it could have gone a week with a battery hooked up backwards. I'd also be curious to know if any of the 12 volt house systems were working during that week.
The very same thing I was thinking.

The way Winnebago designed that battery compartment, the tops of the batteries sit very close to the bottom of the battery compartment cover, and the bottom of the cover is edged by metal. I'm always very careful when I take it off and put it back on to avoid shorting out the terminals. I'm wondering if there were some terminal-clearance issues with the new batteries. Just a thought.
This is the most logical cause of the fire to me.  Most likely batteries in the same group have some dimensional variance and if clearance is tight to begin with, the battery terminals could have contacted the slide.

OLDRACER said:
It might be possible the battery suffered an internal short, which with all the available amperage could have resulted in the fire.
That's another possibility I was also thinking about but not likely with AGM chemistry battery IMO.  We had a Camry several years ago and my wife called me one evening (she was visiting a friend) to say the battery "exploded".  Sure, I thought but drove over to the car, lifted the hood and sure enough most of the top of the battery blew off making a huge mess under the hood.  :eek:
 
The kids made it home last night safe and sound. I checked it out this morning and two of the batteries were really burnt. You could also tell it was mostly isolated in one corner. The cover to the batteries which is held on by four metal turn clasp was melted and the carpet that was on the top side burnt. The heat generated by the batteries underneath caused this. When they took the cover off is when the fire fire actually started. My son put it out with the fire extinguisher.

Side note on the fire extinguisher. The small one that came with the motor home was just enough.... Just. I will be mounting a second, larger one underneath just in case if there ever is a next time. Maybe just a little paranoid now.

Back to the battery cover. It looks as though this is made out of some kind of fire resistant plastic or fiber... Not metal. The metal clasps are not burnt at all. The fire marshal said it did its job by isolating the compartment underneath.

As I said earlier, the firemen disconnected the cables, removed the hold downs and pulled the batteries so this will not be any help in finding the root cause. I didn't see any burnt hold downs either.

As far as a load on it the week previous... I picked it up from the motor home repair shop and brought it to the storage unit and plugged it in where it sat a week. The refrigerator was on but that was about it. On Friday my son picked it up from there in the afternoon, loaded it up and drove about two hours away. They plugged it into a 30 amp circuit. The fire marshal also checked this and said everything was wired correctly on the feed panel. The incident happened a little over 12 hours later.

We are meeting with the service manager tomorrow. I'll let you know what we find out. My main concern is finding out what the root cause was as I don't want it to happen again. Stay tuned. Thanks for your advice and feedback. I appreciate it very much!
 
Rene T said:
Kev, how about putting a thin sheet of rubber over the terminals something like rubber from a old inner tube.
Rene, as soon as I saw the cover's metal edge (the 1st time I took it off), I put a band of heavy duct tape aound the entire metal edge. Just the extra thickness of the tape made it more difficult to get the cover pressed down so it would latch. It sounds like the OP's cover might be constructed differently than ours. Still, I'll be very interested to hear what caused the fire.

Kev
 
aribb said:
...Side note on the fire extinguisher. The small one that came with the motor home was just enough.... Just. I will be mounting a second, larger one underneath just in case if there ever is a next time. Maybe just a little paranoid now....
Anything Mac The Fire Guy sells is a great fire suppression protect.  Mac does RV seminars around the country and sells non-dry chemical extinguishers.  We have a large extinguisher by the front door, in the bedroom and two little ones under the galley sink.

So glad your kids got home safely!
 
Thanks John. We are glad they got home too.

I met with the service manager yesterday and inspected the batteries and coach. None of the battery hold downs or studs had any burn marks on them whatsoever. The top cover, although melted by the heat generated from the batteries has an aluminum band around it and four metal clasps, neither of which showed any signs of arching or burn spots. There are two batteries that are completely melted. There is remnants of the battery cable protective outside casing melted on these two batteries. One battery clearly has a black residue on the negative and red on the positive. The other looks like black on both terminals although it could be red but burnt so bad it looks black.

Here's my questions to all you electrical wizards out there. Could one of the six batteries have been hooked up incorrectly (Positive cable on negative and vice versa), sit there for a week hooked up that way and then heated up to the point of melting? Or.. could an AGM battery short out internally and melted? Wasn't there an new airliner that was grounded because of a battery melting? Or... could the inverter or something else on the motor home caused a battery to overcharge causing this situation? The service manager and I are open to any good explanation of what might have happened. He is willing to cover everything if his technician or a new battery was at fault but he has not come across an issue like this before. I also don't want to have him cover something that may have been out of his control. Any feedback again would be appreciated.
 
Andy, the Boeing 787 battery fire you mentioned was a lithium battery issue - not a lead-acid battery issue. As I said in my first post, I cannot see how a battery could be hooked up backwards for a week without burning up and causing all kinds of electrical problems long before that, but I'm no battery expert. AGM batteries were specifically designed to live in the rough-and-tumble world of fighter aircraft, so they could operate reliably in any position and take a beating. They are batteries, however, and while I doubt that an internal short is likely with a new battery, I suppose it's possible.

I think the most likely scenario is that something came in contact with a battery terminal or cable after the new batteries were installed. Like I said, it's a tight fit on top of those batteries. Maybe the coach had to bounce down the road for a few miles before a loose cable made contact with something. By the way, after you described your battery-compartment cover, it sounds exactly like mine - edged with metal.

I'm still unclear as to whether or not the house 12 volt systems were functioning, or if the battery disconnect switch was even on after the batteries were replaced. The fridge you mentioned is powered by 120 volts AC, so it runs off shore-power, generator-power or inverter-power. Your batteries are charged by the converter, but no charging takes place if your house battery disconnect switch is off.

It may take someone with some specific training to determine the source/cause of the fire. I doubt I'd rely on the shop that last worked on it to determine that. It's certainly not in their short-term interest to point out any mistakes they may have made. It's just awfully coincidental that this would occur right after they worked on the system that failed. I guess it comes down to how far you want to pursue the issue.

Kev
 
Kevin,
Thank you for your insights. I agree with you that an outside "expert" will be needed to help make this determination. I will call Winnebago tomorrow and see if I can get any wisdom for them as to what might have happened. Another option would be to call the insurance agency and ask them if they had an expert in the field. Thanks again. Andy
 
What Kev said.

It's just too much of a coincidence that the problem occurred a) after the dealer replaced the batteries and b) the coach was driven on a trip which points me to the batteries making contact with the slide floor.  I would measure the size of the remaining batteries - use a ruler or board so you can accurately measure the height/width/length of the batteries and allow for the positive and negative terminals and how the clearances might have changed when the cables/lugs are bolted down.

I would call the battery manufacturer and kick the situation around with them, particularly the susceptibility to a melt-down or fire due to overcharging.  There are reports of AGM battery thermal runaway situations, so it certainly is plausible this could have happened.  Google "AGM thermal runaway."

So I think you have one of two situations here - a battery being externally shorted or a thermal runaway due to a battery defect.

I don't think you mentioned the battery brand.  At this point I would sell all of the batteries to a scrap dealer (they are worth over $50 as scrap lead) and replace with Lifeline brand.
 
"The other looks like black on both terminals although it could be red but burnt so bad it looks black."

If there is enough of the covering left you may be able to slice thru it and determine from the cut edge what it's original color was.

A good fire investigator can look at wire ends and tell if they arced and burned or if they overheated and parted. Depending on your local fire department you might be able to have one of their investigators come and take a look. If they think you're trying to get them in the middle of a debate they most likely won't come by, but if you and the shop both convince them that you want to be educated on what may have caused it to prevent another fire they may just help.

Ken
 
I know it is a long shot, but check the output on your battery chargers. I had to replace two of my six, 4-d batteries due to a over charging charger, it boiled them, and they were glass mat batteries. My charger did not step down as it was supposed to, and was delivering 18 volts when plugged in to shore power. Also had to replace my inverter,charger as well.


Lee
 
Back
Top Bottom