Lithium batery Fire and Electrocution risk in Hybrid,Electro(?)

[ajm]

In the News today in Europe:

Due to the increase in Vehicles(EV,Hybrid) with Li-ion batteries, firefighters and rescue workers throughout the world are struggling to develop new methods to put out fires.

Conventional methods and materials,seem to have less impact on a controlling a burning Li-ion Battery.

Recntly an EV parked in an outdoor park caught fire in the German city of Stuttgart. After using 700kg of CO2/Fire hydrant ,the fire was still not possible to control which would have not been the case with Petrol/Diesel..Then they brought a 40-foot container filled with water and put the car into it.After 4 days in quarantine,they took the car out thinking it was safe. Guess what,in a few minutes it started burning again! In the statement said that 65% of the Car-fires reported in EU last year were equipped with Li-ion Batteries.

In addition ,although Theoretically  the Safety-mechanism "Cuts-off" power to the vehicle immediately after an accident,it seems there is no 100% solution to reduce the Voltage at all places where the rescue worker might touch/cut through. Rescue personnel are now required to have training based on vehicle wiring diagrams, to decide within seconds where to cut through the chassis and save the passengers without electrocuting themselves.In one case,the Rescue team had to call Tesla in USA,to get information. Tesls had specifically instructed to keep the wrecked car in an outdooe/free area,away from other cars and not indoors.

Therefore it is recommended to keep a diagram showing the safe and risky areas , inside the vehicle to be used by rescue personnel in case of an accident,which will be obligatory soon.

 

Wonder if our Firefighters/Rescue workers/Drivers are prepared/trained to handle these new challenges,or plan it the usual way "to learn by doing and by mistakes"..

Edited March 26, 2018 by ajm

[Twin Turbo]

Just wait till   local wizz crashes a hybrid !    

[ajm]

in EU region,now they are considering to bring stricter regulations for Basement parking and charging stations. Since many fire incidents were reported overnight during charging and the inhabitants of the building needed to be evacuated from the smoke which continues for days!

[vag2]

is it a Tesla specific problem or related to all(Leaf,Prius,Fit)? At least the i8 recently did not burn after crashing(in to water ?)

[ajm]

  On 3/27/2018 at 8:48 AM, vag2 said:

is it a Tesla specific problem or related to all(Leaf,Prius,Fit)? At least the i8 recently did not burn after crashing(in to water ?)

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weakness in all Li-Ion technology;

Cell contains a series of materials which are very reactive, in particular

1. lithium in the active materials

2.Conductive-salt lithium-Hexafluorphospaht

3.cathode releases oxygen during decomposition   

And risks of the "Thermal-Runaway" = thermal overspeeding of the cell

1. anode and cathode become unstable near maximum operating temperature

2. exothermic reaction with electrolyte

3.heat development (coupled with 1)

  heat=> Exhothermal reaction=>more heat=>.more reaction....

external factor like Overcharging,HIgh Environment temperature,External Short circuits,Deformation,Shocks and Vibration contribute to such situations ending with Cell Fire.

Solid-state Batteries without any unstable materials in the Cells seem more stable, but cost is prohibiting their use in mass-production vehicles yet.

So until some breakthroughs are found, we have no alternative but to know the risks and how to minimize damage in an Emergency.

 

 

 

 

Edited March 27, 2018 by ajm

[Clark'sson]

  On 3/27/2018 at 12:40 PM, ajm said:

external factor like

Overcharging,

HIgh Environment temperature,

External Shortcircuits,

Deformation,

Shocks and Vibration 

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AKA SRILANKAN DRIVING CONDITIONS 

Edited March 27, 2018 by Clark'sson

[ajm]

  On 3/27/2018 at 2:45 PM, Clark'sson said:

AKA SRILANKAN DRIVING CONDITIONS 

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yes ,maybe except overcharging and External short circuits(by jump start only, not after accidents) which could be avoided.

This diagram of Internal-Runaway and Cause-Effect Relationships from an Autmotive Research Journal(Sorry no English version) shows in detail.

Edited March 28, 2018 by ajm

[vag2]

wonder how many of our mechanics,drivers, highway patrol and rescue staff are aware of how to handle the specific risks of these batteries. Not only during use and an emergency,but also storage and recycling safely.

[vag2]

and looks like another EV crashed and burned just recently, this time in the US.

" The SUV became engulfed in flames after its battery packs caught fire following the collision, prompting Tesla to send a team of engineers to the crash site "

http://www.thedrive.com/tech/19702/tesla-investigating-fatal-model-x-crash-releases-statement

Looks like a very High burning temperature,more like scorched due to extreme heat than burning out. Thermal Runaway?

 

Edited March 29, 2018 by vag2

[ajm]

wow,that looks really bad. Tesla even saying the battery has burned faster than expected in the design. No matter how well the battery is insulated,the massive shock from a head-on collision like this will be transferred to the battery. And it could trigger the "Thermal Runaway" scenario as mentioned in above cause-effect diagram.if a hard cover is used around the battery,the whole thing could explode due ro rising heat and pressure.I think the Hybrid and EV makers will also have to think of some shock absorption methods for the Li-ion batteries,not just insulation and fire proofing with hard cover as it is today.

[Clark'sson]

  On 3/29/2018 at 8:38 AM, ajm said:

wow,that looks really bad. Tesla even saying the battery has burned faster than expected in the design. 

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So They expect the battery to burn at even some rate. Knowingly putting such batteries in cars should be considered manslaughter.

[vag2]

  On 3/29/2018 at 2:04 PM, Clark'sson said:

putting such batteries in cars should be considered manslaughter.

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The model-X Tesla has the best NHTSA safety rating in the world for an SUV. Are the Crash tests of Hybrid,Electrics done with these unstable Li-ion batteris on board? I doubt it,because otherwise at least one of the prototypes would have caught fire after the crash.

[ajm]

  On 3/30/2018 at 8:11 AM, vag2 said:

Are the Crash tests of Hybrid,Electrics done with these unstable Li-ion batteris on board

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I doubt they are full-series production vehicles. Most of the time,the traction for the test vehicle comes from external rollers,belts etc. So no need to even have the hi voltage battery inside,while 12V system can supply the Airbags and seat belt tensioners.Crash tests provide insight into the protection offered by the vehicle from an impact itself. They do Not test the real-life scenario of secondary failures like fire,explosion resulting from the impact. This is usually handled on the design phase, by safety reviews like FMEA,FTA, 8D. And fire risk would be wiped off as a "multiple/double" failure case.

Edited March 30, 2018 by ajm