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RandyA

Trailer Fire - need some help please.

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Don't know, carl.  My knee-jerk is to have batteries as far away from exit door as possible.  A steel heat shield couldn't hurt either.  As Sehc just noted liquid heating and cooling tubes were not used in my GC application.  I was playing outside the engineered safety parameters of the original design application with my install.  In retrospect, probably not a good idea.  There is a risk factor for any battery be it flooded, Gel, AGM or whatever.  We know the rules for proper venting and placement for each of the above.  Hydrogen gas explosions with lead-acid batteries are known to be commonplace if they are not properly vented.  Those rules are not entirely applicable to Li-Ion - that is where I screwed up.  You know what ASSUME translates to :).  There evidently is more to all the new airline restrictions on Li-Ion than media hype.  We still have a lot to learn about the safest way to incorporate used Chevy Volt batteries into our rigs.  I still contend knowing the donor for used batteries is important so we can avoid incorporating units from a damaged pack.  I let my mind wander into "what if" mode last night - like "what if" what I believe to be an internal short in a damaged battery had developed while the cart was on the back of the Volvo running down the road at 60 mph or simply parked with no one around?  What are (were) the odds of this happening? (for me it was 100%).  How many other similar known cases do we have to develop a statistical analysis?  I don't have those answers (yet) and can only speculate at this point.   It would be nice to discover that this was just a 1 in a billion fluke. 

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Do bring up a lot of questions. There are several using these batteries and no problems reported yet. I will be later. Need to get back to work to have monies for this. Lol

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Maybe sometimes being an "early adopter" has a down side.:o

If someone as experienced, and careful as you has a bad experience, I'm gonna just sit back and watch for a while.  Thank you for being so open about this.

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1 hour ago, rickeieio said:

Maybe sometimes being an "early adopter" has a down side.:o

If someone as experienced, and careful as you has a bad experience, I'm gonna just sit back and watch for a while.  Thank you for being so open about this.

We had planned to use Volt batteries in our upcoming trailer build. I'm reconsidering this at this point. There are other chemistries available (LFP). They cost more. But not as much as a new trailer. Or perhaps my life. Or my wife. Or my dog. 

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6 hours ago, RandyA said:

I was playing outside the engineered safety parameters of the original design application with my install.  In retrospect, probably not a good idea. 

We still have a lot to learn about the safest way to incorporate used Chevy Volt batteries into our rigs.  I still contend knowing the donor for used batteries is important so we can avoid incorporating units from a damaged pack. 

 

Randy,

Anything you can share on your GC battery setup. Any LVD (low voltage disconnect) and more important, what charge controller was used and what HVD (high voltage disconnect) was used?  Just trying to understand what might be the true root cause and any Chevy Volt battery lessons learned for those using or planning to use them.

"Lithium ion" batteries are not all the same. While the lithium cobalt oxide (LiCoO2), are the ones you hear about causing laptop, cellphone and hover-board issues, they are liked by manufacturers because they offers high energy density, but as stated presents safety risks, especially when damaged. Lithium iron phosphate (LiFePO4), lithium ion manganese oxide (LiMn2O4, Li2MnO3, or LMO) [The first generation of Chevy Volt batteries referenced in the discussion] and lithium nickel manganese cobalt oxide (LiNiMnCoO2 or NMC) [Tesla Powerwall I believe?] offer lower energy density, but longer life and less likelihood of unfortunate events in real world use, (e.g., fire, explosion, ...). BUT, the care and feeding of any of them is critical. Not to be treated OR charged like a FLA or AGM.

The heating and cooling systems on the actual vehicle Chevy Volt battery system is intended for environmental control of the batteries, rather than a safety system. Cars live in very cold (NE currently!!) or hot environments (Death Valley!) and operate (and charge) optimally within a certain temperature range. The Chevy Volt battery does have an actual BMS (battery management system) that manages the individual cells (all 288 cells) and does include thermocouple measurement as the battery bank (24 or 48VDC) level [two per bank I think]. Cell voltage balance across the bank is critical. Some have chosen to do this manually and check it periodically. Others may choose a BMS system.

You can get a BMS system for a Chevy Volt 48VDC battery bank. It's about $50-60 and available on AliExpress (China). Have the link somewhere if anyone is interested. I have not tested it. Have seen a YouTube video, but no long term results. Maybe someone out here can relay any personal experience.

Let the battery gurus appear [also other Lithium-ion battery threads on the forum], but mostly interested here in any feedback on the "outside engineering safety parameters" that may be a contributing factor [If you are willing to share - publicly or privately].

Thanks for all your really forthright sharing to date and wishing you a speedy recovery.

 

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I really don't want to share a schematic at this point.  I can tell you what I built limited current to no more than 15 amps and shut the charger down at 49 volts.  In the golf cart there was no low voltage shut down device, only a digital meter with an alarm for both high and low voltage that I had to react to accordingly.  I had built a temperature sensor circuit that would disconnect the charger from the batteries when being charged but had not installed it.  Checking voltage on individual cells was done with a single digital meter and a multi-contact manual rotary switch that was plugged into the battery as needed.  It was not connected at the time of the fire.

Keep in mind these were batteries that were totally disconnected from anything.  There was no charger involved and nothing active that could pull any current.  While having no load at the time, all circuits were properly fused with the correct gauge wire for the buck converter, lights, horn and solenoids.  There was even a 300 amp fuse on the main positive line that went to the controller and eventually the motor.  I've thought about this for hours trying to come up with an answer as to why.  It doesn't follow logical failure patterns as the two batteries were completely disconnected from any load or charging device. The failure mode is speculation - If you or someone else has another idea I would really like to hear it.  Yes, items designed to prevent failure can fail.  But short of someone getting hold of my propriety key needed to energize the two DPDT continuous duty solenoids that controlled reverse and forward while at the same time finding the red plastic key that cut off all battery current is even less logical.  While someone intentionally starting a fire externally cannot be totally ruled out such an action does not fit the location or time. 

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Thanks Randy for sharing. No charging or load to LiMnO2 batteries seems illogical that would initiate a thermal issue. The 49.0 charge limit is well below the general 12S LiMnO2 batteries of 50.4V.

The only "theory" I can throw out is that a single cell got significantly out of balance and significantly exceeded the cell 4.2V limit and went into thermal runaway. Would expect this in LiCoO2 batteries if there was some physical damage somewhere. Take a look at the Boeing 787 issue. [Might have to have the FAA come investigate you GC - did it fly? :o]. Not aware of this being an issue in LiMnO2, but I don't deal with this every day. I do believe that you stated, and I agree, the LiFePO4 batteries are among the safest of the  "Lithium-ion" batteries. I've seen them severely damaged and "abused", and not cause any thermal issues. They have trade-offs. But they all have special care and feeding needs.

Other armchair theoretician ideas?

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On 3/16/2018 at 9:31 PM, phoenix2013 said:

Randy, I use this link for photo-posting  http://photoposting.is-great.net/?i=2   I believe that is what Jack is suggesting, but I couldn't make his work when I tried it.

Paste it in google and their site comes up, unlike photobucket you do not have store your pictures with them to use it. You go find the picture IN YOUR COMPUTER, ANYWHERE,  and grab it (Sect it) with their control. They grab it temporarily and instantly give you the image code, which you copy and paste into the thread, done! You can go then to the next picture, the next picture, etc. Couldn't be easier. 

I still have a photobucket account but it's a PITA by comparison. The only money they got out of me was $14 bucks to avoid million of their stupid ads trying to use it, but I haven't been back with them since I discovered http://photoposting.is-great.net/?i=2

H

Today I'm getting a BAD GATEWAY error.  I hope it's just temporary.

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Dolly - is that the new rv industry fad "garage walls optional" lightweight toyhauler? 

At least is has clearance for The World's Steepest Approaches found at fueling stations...

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