LEAF Fire in North Texas

[XeonPony]

Car fires happen, and gasoline is not always the cause.

True that, but if not gasoline (or oil), its usually the heat off an ICE that is the cause. The idea that this fire is due to a 12 volt electrical short seems unlikely (i.e., impossible) to me. Unless the 12 volt is run through a a very carefully wound coil (like an old style cigarette lighter) or a dead short across the battery terminals with a very heavy gauge wire, nothing 12 volt underneath that dash could produce the heat necessary to start a fire. But if either the 12 volt system or the traction battery was shorting you would think it would a) make a lot of noise and b) dramatically effect the operation of the car such that you would not find yourself driving “normally” until you noticed smoke.

Since no one was injured (thankfully) I can understand the relative lack of interest in the cause, but I would think your insurance company would be looking to push the cost onto someone else so at least they would send someone out to have a closer look.

You clearly do not have much experience with 12v! It is thee most fire prone voltage out there! just takes a high resistance connection and heat starts to build up in the plastic and on it goes till it goes poof! in flames! been there don that on systems from my solar power system to my diesel truck to my 92 4*4 ( I had to do allot of repairs from PO hacks)

[jpadc]

You clearly do not have much experience with 12v! It is thee most fire prone voltage out there! just takes a high resistance connection and heat starts to build up in the plastic and on it goes till it goes poof! in flames! been there don that on systems from my solar power system to my diesel truck to my 92 4*4 ( I had to do allot of repairs from PO hacks)

We are talking about in a LEAF, under the dash. Everything is fused and a loose connection with high resistance would require a fuse failure (and likely the main fuse as well) and would likely kill the tiny 12 volt LEAF battery long before that type of heat built up. Its not like the materials under there are HIGHLY flammable. Take a torch to most of that plastic, it has to get really hot to flame. Now maybe if the car is charging overnight and the inverter keeps the 12 volt powered up as a loose connection heated up, but that would require a power draw on the connection and what's powered up under the dash when the car is off???? Its not like the car was driving for hours before the fire was going so it would seem (if caused by a 12 volt source) it had to take awhile to develop that level of heat.

I can accept its POSSIBLE, but you have to admit its just extremely unlikely in a newish LEAF. I'm saying I for one would sure would like to know the cause rather than dismiss this as just "another" car fire.

[Valdemar]

A loose connection with high resistance is guaranteed to never cause a fuse failure, unless by "failure" you mean the failure to prevent from fire.

[palmermd]

Also the area in question has the cigarette lighter/ aux power port which has a large fuse (I believe 15 amp).

[XeonPony]

You clearly do not have much experience with 12v! It is thee most fire prone voltage out there! just takes a high resistance connection and heat starts to build up in the plastic and on it goes till it goes poof! in flames! been there don that on systems from my solar power system to my diesel truck to my 92 4*4 ( I had to do allot of repairs from PO hacks)

We are talking about in a LEAF, under the dash. Everything is fused and a loose connection with high resistance would require a fuse failure (and likely the main fuse as well) and would likely kill the tiny 12 volt LEAF battery long before that type of heat built up. Its not like the materials under there are HIGHLY flammable. Take a torch to most of that plastic, it has to get really hot to flame. Now maybe if the car is charging overnight and the inverter keeps the 12 volt powered up as a loose connection heated up, but that would require a power draw on the connection and what's powered up under the dash when the car is off???? Its not like the car was driving for hours before the fire was going so it would seem (if caused by a 12 volt source) it had to take awhile to develop that level of heat.

I can accept its POSSIBLE, but you have to admit its just extremely unlikely in a newish LEAF. I'm saying I for one would sure would like to know the cause rather than dismiss this as just "another" car fire.

I'm sorry but again your lack of experience is clear here, often a high resistance (NOT LOSE) will rarely trigger the fuse but more then capable of generating enough heat to build up to cause ignition temps to be reached.

Just because there is a fuse does not mean you are 100% safe! (Even your standard breaker is not all that sensitive in a house unless using an arc fualt, gfci breaker with good grounding!)

All so this heat can be very rapidly built up.

As to what is powered? Allot, any time you can turn any thing on via a button there is power flowing. The question is how and why it happened

the why most of all, so far all the connections in the leaf are very well don.

I live off 12V still, and fuses do not offer me good sleep, being super care full and thorough with every wire connection, and using very care fully sized high speed fuses with just enough of rating to meet the load, and checking it every couple days.

12v is a dangerous voltage, it is the standard but that is not for safety reasons. (It is a miracle there are less fires from allot of the wiring they use in RVs and quality of general public wiring skills)

As for the bottom statement, I do 100% agree, it is a rather unique failure and deff needs to be under stood!

[XeonPony]

A loose connection with high resistance is guaranteed to never cause a fuse failure, unless by "failure" you mean the failure to prevent from fire.

Well said.

[TimLee]

Sharp well informed input from Valdemar and XeonPony.

To start presuming 12V is low risk is a grossly inaccurate understanding of the reality.

TVA set up some Electric vehicles for testing.
One had a fire.

The fire was from the add on 12V monitoring system.

12V can be an absolute fire hazard if not done correctly.

Personal experience: Grossly inadequate fan blower control switch on a Ford Pinto.
Fortunately it failed without creating a fire.
But the degree of overheating and meltdown that it experienced easily could have created a fire.

Nothing all that safe about 12V.

The lack of fires with 12V is dependent on high quality connections and well designed 12V devices.

Think about that the next time you plug in an inexpensive made in China 12V device in your 12V outlet in your car and decide to leave it functioning unattended.

You may find your car and your garage and house on fire.

[Shawn75067]

Very interesting and informative conversations. So either way, 12v or high power, very odd that my car caught fire. I did not have any cheap connectors plugged in, I did have a high quality lightning cable connected to the USB & plugged into my iPod Nano which fell victim to the fire; however the flames came through the plastic in the middle of the tray area of that console, closer toward the cup holders and not where the USB or cigarette lighter area was.

[jpadc]

To start presuming 12V is low risk is a grossly inaccurate understanding of the reality

Of course its low risk... Most every car manufactured in the world uses 12 volts and has for years. Car fires (of all types) are EXTREMELY RARE. By definition that is low risk (ask an insurance agent if you doubt that statement). Yes, a 12 volt fire is possible, but as you note, lots of melting is way more common than a fire. The point here is that dismissing this fire as just some freak 12 volt accident, while possible, is not PROBABLE. That's why people here "dismissing" this as "cars catch on fire. Nothing to see here, move along" is a mistake IMHO.

As a proportion of total number of cars manufactured and sold, even ONE LEAF fire makes this car a statistically higher risk than most any other on the road today (not really a fair thing to say, but technically accurate).

[Firetruck41]

I wouldn't say "it's no big deal" that a Leaf caught fire, but I am not worried about the HV side at this point. I would say it is probably more common for modern car fires to be a result of a 12v issue, than a fuel/fluid/engine heat problem. My suspicion, is that the fire is similar to other cars in that it is 12v in origin, and I will need some convincing that it is otherwise, as my experience points towards 12v. I would very much like to "know" the cause, but until then I will keep my suspicions.