2010 Prius Caught Fire

Sorry to hear that and count your blessings you were not in the car.

 

i would be concerned to get near the car in case it exploded.

 

This is what I carry in my truck based on recommendations from several firefighters on TacomaWorld. You may be able to find it locally at a comparable price. It's important that it be ABC type (US).

 

When you think about it, there's not much holding back a potential fire in a Prius. Over a kilowatt of stored potential energy is up against solid-state switches inside the inverter (correct me if I'm wrong and there is actually a physical switch).

If that silicon barrier (which is usually pure silicon doped with impurities) lets electrons through for some reason, and allows a runaway effect, causing the battery to short out through the inverter, a fire such as this isn't surprising. Even if such events are rare, it's worth considering whether a physical battery disconnect switch in the car (such as the one on the battery itself) wouldn't be a good idea.

 

Good idea. Our car is starting to get weighed down with all the stuff I keep piling into the under hatch floor tray, maybe I should balance it with a fire extinguisher nearer the front, say under one of the front seats.

 

A fire under the hood is hard to extinguish without opening the hood, and the "window" for opening the hood before flames make it impossible, is quite short in most cases. I've witnessed several vehicles go up in flames, while people vainly tried to spray the fire extinguisher through the grill, to no effect, because they couldn't get the hood open.

 

When the Prius is powered down the HV batt is isolated from everything outside of the HV batt case. The connection from the HV batt to the Prius is on the terminals of these relays. Both the Pos & Neg leads have separate relays & there is an "extra" relay in the Pos lead that supplies power through a "precharge" resistor during startup to keep from arcing the contacts of the Pos relay.
During the power-down sequence a test is run to make sure none of the relay contacts are stuck in the operated position (contacts welded).
If/when I can find the source of my info I will add it to this thread.

added 120414 1900
This document talks about the Gen1 & Gen2 Prius System Main Relay (SMR) on page 6...
Page 6 also has a basic schematic of these relays. The Gen3 follows the same layout.

http://www.autoshop101.com/forms/Hybrid03.pdf
"The System Main Relay (SMR) connects and disconnects power to the
high-voltage circuit based on commands from the HV ECU. A total of
three relays (one for the negative side and two for the positive side) are
provided to ensure proper operation.
When the circuit is energized, SMR1 and SMR3 are turned ON. The
resistor in line with SMR1 protects the circuit from excessive initial
current (called `inrush' current). Next, SMR2 is turned ON and SMR1
is turned OFF, allowing current to flow freely in the circuit.
When de-energized, SMR2 and SMR3 are turned OFF in that order
and the HV ECU verifies that the respective relays have been properly
turned OFF."

It seems the test is performed during power-down rather than power-up as I thought.

 

Good to know.

 

Glove compartment fire extinguisher is a "Halon" type originally bought for my airplane, made by International Safety Systems of Atlanta, Georgia, Model 12C. That one is quite old. The second fire extinguisher is attached to the back of my seat and is a "Cease Fire" Halon plus ABC powder Double Agent Extinguisher made by Cease Fire Corporation of West Chester , PA. Halon is a chlorofluorocarbon and thus those exact extinguishers may no longer be made. I keep them because they are effective for their weight and size and I must have them handy to quickly exit my vehicle and extinguish the fire before it gets out of hand. Seconds count. In airplane I also had a larger ABC extinguisher bolted to the floor between pilot and copilot seats as I was sitting between two 18 gallon fuel tanks.

 

thanks!

 

Strongly agree. Hood must be opened quickly and extinguisher sprayed at base of fire. Both of my car fires smoked from under the hood which gave me just enough warning to pull over, stop, pop hood latch, grab fire extinguisher, run to front of car, undo safety latch (which was getting hot!), open hood , and spray extinguisher. The other two cars were strangers who already had their hoods open but were staring helplessly at flames from the engine compartment. Much less stress. But be careful,opening hood as flames tend to kind of billow out at you which can singe eyebrows, etc.

Unlikely as insufficient gasoline vapor in engine bay and too much ventilation area. Gas tank can, of course , explode and that forms an impressive mushroom cloud of fire, but only if ignition of vapors in tank occurs. If fire is in front engine bay and gas tank is in rear I felt safe as long as I could keep the fire from spreading to rear. But if rear is engulfed I would expect and prepare for an explosion.

 

Something about the pictures doesn't look right. I'm not a fire expert, not calling bull shit yet. The damage seems so uniform.

 

when you say 'yet', is there more to come? maybe the garage door spontaneously combusted, and set the prius on fire.

 

My solution: after buying a NOCO Genius 120V extension port suggested by someone on Prius Chat, I had it painted to match the car (pennies really) and then mounted it on the front corner of the bumper, right next to the windshield washer fluid tank. This location is also a good visual reminder to unplug - more noticeable than the OEM black plug hangin' off the black grille. Note: my wall receptacle is on the same side of the car as this NOCO port, the way I park, and immediately by the front patio stairs.

The NOCO mount is painted. The rubber cap for the plug well is black, as it flexes too much to hold paint IMHO.

I also replaced the OEM plug on the Engine Block heater with a solid aftermarket plug, then sealed the cord and pugged it into the NOCO Extension.

For safety with a potential arc fault secured the single-receptacle circuit at the panel with a "CAFIC" or a "Circuit Breaker and Combination Arc Fault Circuit Interrupter".

Why I use the EBH - fast heat on those Winter mornings. My normal commute is too long for exclusive EV power no matter what, so I might as well fire up the gasoline engine at first.

 

Cars always explode in the movies, but in real life it takes a special set of conditions. A confined fuel source (usually a metal gas tank), a heat source (usually a fire) and enough time to super-heat the container to the bursting point. The other way is for gasoline vapor to fill a confined space to the explosive limit point and an ignition source exists.

Most fuel-caps have been made of plastic for quite some time, and this in itself would prevent fuel-tank explosions. Any fire hot enough to boil the gasoline would also melt the cap, therefore the vapor would be vented and couldn't build up enough pressure to burst the tank.

Both are comparatively rare, and the greatest risks by far, are the accident itself and fire, if it ensues.

 

Wow, a Halon extinguisher! Halon is now "banned" (not being produced anymore) and is being horded by aircraft operators, especially the US Air Force. Halon is almost worth its' weight in gold! I have a "standard size portable" Halon extinguisher, same size and shape as my dry chemical extinguisher. I got it quite a while ago just when they stopped making it. Halon is nice because it leaves no residue, unlike the dry chemical ones, which leave a mess. But Halon works best in "enclosed spaces", whereas dry chemical can work well in open spaces, such as an engine compartment (open at top and bottom).

 

I've always carried a small fire extinguisher. I've seen too many vehicle fires that could have been stopped in the first few seconds with a fire extinguisher.

 

As a kid, I had an engine fire erupt (busted fuel line) just as I pulled into work. In my panic, I scooped up dirt and small gravel from the parking lot to put out the small fire. It worked! LOL

 

It helps to be able to think in an emergency, but thinking beforehand is a bigger help.

Risk-management requires risk-assessment, which requires thinking.

Risk-avoidance (let's make another rule) does not require risk-assessment, which requires no thinking.

 

Good point.
The three times I have put out car engine fires were with the dry chemical extinguishers and they did leave a bit of a mess. The side draft carburetors on the Volvo had to be cleaned but did work afterwards. But still far cheaper then letting the fire go!