Smokin' Hot Tesla

[SC Tiger]

Can't find the video anywhere else yet.

 

 

https://jalopnik.com/surveillance-video-of-tesla-exploding-in-shanghai-parki-1834211204

 

 

Edited April 22, 2019 by SC Tiger

[gamboolman]

 

Edited April 22, 2019 by gamboolman

[janice6]

The modern demands on electric "stuff" require the highest energy density available to get the most performance and longest duration.

The problem with energy density, is that when the current density is very high, it takes a very slight imperfection in the battery to cause a short or overheating to develop.

When a short circuit within the battery develops, the high current density tries to pass through the small imperfection.  This produces a very high temperature which in turn causes other parts of the battery to fail.  The failure of one battery may cause a huge thermal shock to the adjacent batteries, which in turn causes them to fail.

This type of an avalanche failure is not uncommon in electrical devices and semiconductors that operate with a high current density.  Many times the available current is limited and the catastrophic effects are also very limited.  Then you simply have a "failed device" with no fireworks.

Sometimes in an application where the available energy density is extremely high and the available peak current is also very high, this type of failure occurs and it reacts so quickly, that it approximates an explosion.  As in the cases with an electric car.

My point is, that the potential failure probably is within the battery, and it's variability in quality of the manufacturing process.  It doesn't show up unless all the variables are right.  This can happen long after the battery is manufactured, but it is statistically inevitable over time.  Not every battery will fail, but it's unknown which ones will fail.

The fault may not have anything to do with Tesla, but it may be a problem with the infancy of the construction and manufacturing process for creating such a high energy density in that style battery.  Remember that Lithium rechargeable batteries have had this problem infrequently over many years now.  It is now affecting cars rather than flashlights and other consumer rechargeable battery stuff.

 

I have no skin in this game, I don't care one way or another about the manufacturers involved in this problem.  I just think that an objective analysis is deserved.

[tous]

4 hours ago, janice6 said:

This type of an avalanche failure is not uncommon in electrical devices and semiconductors that operate with a high current density.  Many times the available current is limited and the catastrophic effects are also very limited.  Then you simply have a "failed device" with no fireworks. 

 

 

This was known in my day as letting the magic smoke out. 

And people wonder why we always turned out faces away when we applied power to a board for the first time.

Watch out for shrapnel!

The magic smoke is escaping!

It did make finding the point of failure easier.

 

Edited April 22, 2019 by tous

[Gun Shark]

That’s hot.

[willie-pete]

My brother came up for Easter dinner Sunday and showed me a picture of two batteries in his boat. He was going to take it out last weekend and when he hit the start button on the engines, he heard an explosion downstairs.

An internal short had blown the sides out of two batteries.

[janice6]

On ‎4‎/‎23‎/‎2019 at 1:24 AM, willie-pete said:

My brother came up for Easter dinner Sunday and showed me a picture of two batteries in his boat. He was going to take it out last weekend and when he hit the start button on the engines, he heard an explosion downstairs.

An internal short had blown the sides out of two batteries.

Yeah.  I hate it when crap happens.

[SC Tiger]

On 4/22/2019 at 12:41 PM, janice6 said:

The fault may not have anything to do with Tesla, but it may be a problem with the infancy of the construction and manufacturing process for creating such a high energy density in that style battery.  Remember that Lithium rechargeable batteries have had this problem infrequently over many years now.  It is now affecting cars rather than flashlights and other consumer rechargeable battery stuff.

 

The issue (liability speaking) with this is that Tesla makes their own batteries.  It is one of the reasons they have done so well - their battery design.  So - assuming this is true, this is a Tesla issue.

IMO they may be pushing the envelope on their batteries compared to other hybrid and electric car models.  Or it could be a simple manufacturing fault, or even damage from road debris.

[janice6]

31 minutes ago, SC Tiger said:

The issue (liability speaking) with this is that Tesla makes their own batteries.  It is one of the reasons they have done so well - their battery design.  So - assuming this is true, this is a Tesla issue.

IMO they may be pushing the envelope on their batteries compared to other hybrid and electric car models.  Or it could be a simple manufacturing fault, or even damage from road debris.

According to what I read on the subject, Tesla may assemble the batteries into the form factor they require.  But the manufacture of the 18650 rechargeable lithium batteries themselves, are being done by a battery manufacturer.  This reference states that Panasonic makes the batteries.

 

Another reference says that Tesla is considering a new battery design and package, however the article says:  "...“We’ve totally custom-engineered that cell, working jointly with Panasonic to create…an automotive cell,..."

I did not say that Tesla didn't have the liability for the damage, just that it might not be their car that caused the batteries to fail catastrophically.

Now, with the new talk of "supercharging the batteries", the catastrophic failures that do occur, can also start occurring on the charge cycle, due to the high current density and heating resulting from accelerated charge rates. 

Understand that I'm not against this technology or it's implementation, just that high energy density in any form results is a more impressive failure when failure occurs.

Edited April 24, 2019 by janice6

[SC Tiger]

10 minutes ago, janice6 said:

According to what I read on the subject, Tesla may assemble the batteries into the form factor they require.  But the manufacture of the 18650 rechargeable lithium batteries themselves, are being done by a battery manufacturer.  This reference states that Panasonic makes the batteries.

 

Another reference says that Tesla is considering a new battery design and package, however the article says:  "...“We’ve totally custom-engineered that cell, working jointly with Panasonic to create…an automotive cell,..."

I did not say that Tesla didn't have the liability for the damage, just that it might not be their car that caused the batteries to fail catastrophically.

Now, with the new talk of "supercharging the batteries", the catastrophic failures that do occur, can also start occurring on the charge cycle, due to the high current density and heating resulting from accelerated charge rates. 

Understand that I'm not against this technology or it's implementation, just that high energy density in any form results is a more impressive failure when failure occurs.

Gotcha.  Makes sense.

More info will come out.  The thing that scares me is that these things can apparently just spontaneously combust.  It's not unheard of for a gas car to do that but it is rare.  Plus I think the batteries are in a pan underneath the passengers.

To me the tech is fascinating, but there are still issues.  Gas cars have issues too.

[janice6]

1 minute ago, SC Tiger said:

Gotcha.  Makes sense.

More info will come out.  The thing that scares me is that these things can apparently just spontaneously combust.  It's not unheard of for a gas car to do that but it is rare.  Plus I think the batteries are in a pan underneath the passengers.

To me the tech is fascinating, but there are still issues.  Gas cars have issues too.

Yes.  I wholeheartedly agree.  My continuing complaint is that the energy sources we have now are simply fixes, and not the solution to the problem.  I obviously have no answer for what the real energy source will be, but I do know that by simply increasing the energy density of the sources we now have, will result in more catastrophic failures than what we are used to in the past.

For example, in the rare occurrence of a lead acid battery suddenly failing and blowing up under the hood, the damage is fairly limited to the acid washed body panels, and radiator, etc.  due to it's relatively low energy density. If you had a similar battery failure in a battery source such as the proposed increased capacity 2170 style batteries for potential use in the Tesla, you might see the car literally explode.  Again!  I am not against this technology, I am just stating the obvious that is to come.

At one point, the idea of eliminating the storage battery as an electrical source was/is a serious consideration, in favor of replacing it with a Capacitor, that can be charged like a battery and then discharged while performing some function such as running an electric motor.

This results in eliminating the electrolytes in favor of creating an extremely small infinitely porous internal structure that replicates two plates of a capacitor in the form of a microscopic sponge.  This has been done and has been implemented. 

The ugly fact still comes back to haunt the development because to provide a significant electrical charge requires almost an infinitely porous structure of very small volume.  Now we are back at the same problem as the battery, in that the energy density of the device is so high that two forms of failure will occur occasionally. 

One, will be the breakdown of the dielectric at a point that will produce an avalanche failure of the whole device.  The second, is that the electric field strength can become so high that it can put a physical mechanical stress on the capacitor that results in it's "explosion".

So far all we have done is change the configuration of the energy sources we have, we have not created an entirely new "better" energy source.  Oh well.  that's the task for tomorrow!

[Wyzz Kydd]

I think another disadvantage of the Tesla battery is that as the charge declines power declines with it.  I'm not sure why that is so but I do know a Tesla with 50% charge will be a lot slower than a Tesla with a full charge whereas a car with a half a tank of gas has the same horsepower as the same car with a full tank.  

One of my buddies with a Tesla kept trash talking my Camaro, so I invited him to a race, 20 miles or so from the nearest charging station.  He declined.

[janice6]

  As the high peak battery load  increases the capacity of the battery decreases, limiting how much energy it can deliver.  Load it to less high peak currents and the battery capacity will be greatly extended.

Technically correct or not, one way to think of this is that the electrolyte that is between the plates of the battery is suddenly depleted with load, but given more time, the chemicals can migrate from elsewhere to increase the chemical concentration between the plates, and provide some recovery.  High peak currents also cause significant heating of the electrolyte.

Here is one example of a battery decrease in energy versus the discharge rate:
 

[Wyzz Kydd]

So if a fully charged Tesla can do 0-60 in about 2.28 seconds how much would it theoretically lose when the charge is at say 50%?

[janice6]

16 minutes ago, Wyzz Kydd said:

So if a fully charged Tesla can do 0-60 in about 2.28 seconds how much would it theoretically lose when the charge is at say 50%?

I can't answer your question since I haven't had any interest in the field other than for my own purposes (Not tesla oriented).  I would suggest that any performance of the Tesla battery pack is simply going to be a reflection of each of the individual 18650 cells it is comprised of.  Therefore, if you looked up the characteristics of an "unprotected 18650 lithium rechargeable battery" you would undoubtedly get the answer to your question.

Because you connect these individual cells in a configuration that suits the electrical requirement of the car, it doesn't negate that the overall performance is a multiple reflection of the single cell.

[tous]

If I were a young engineer just starting out, I would go into power generation and especially the science of batteries.

A lot of neato work to be done yet.

[Dan Guillory]

I see the Tesla’s lined up at a nearby charging station all the time. The juice comes from a natural gas fired power station.

ALL of the regional power stations in my home area use natural gas to generate energy. 

So....I guess I don’t understand the environmental advantage of charging up electrical cars using fossil fuel sources?

[Wyzz Kydd]

Tesla’s are not about saving the environment; they’re about virtue signaling and the power of government subsidies bringing non-competitive products to the marketplace.

[janice6]

7 hours ago, Dan Guillory said:

I see the Tesla’s lined up at a nearby charging station all the time. The juice comes from a natural gas fired power station.

ALL of the regional power stations in my home area use natural gas to generate energy. 

So....I guess I don’t understand the environmental advantage of charging up electrical cars using fossil fuel sources?

This is a case where the usual approach is to move the problem from "me", to someone else and then calling it a solution.  My electric "thing" is clean and unpolluting while I am using it, but the pollution in reality has simply been moved from me, to the power company.  Out of sight, out of mind.

The argument will be for economy of scale, that means the power company is a major source of pollution now and since it's being centralized, I can force them to do all kinds of things to appear to clean up the pollution.  Government regulation work better on a centralized problem, you can now grab the CEO by the nuts to make him comply, rather than a million different individuals that have neither the time, money, nor inclination, to solve "your" problem with their pollution.

As with any social problem, by making it the government's problem you give the politicians an excuse to tax, spend, and buy votes, by appearing to solve problems, while all along they are more ignorant than anyone with regards to anything approaching a unique, inventive, and believable solution, to any problem.

Remember that politicians have no area of expertise and are only in the job for the money, influence, and power, derived from legally applying force and punishing by taxing the citizens. 

Of course I'm a bitter old man.  I would change my tune if there were any, any, training requirements for producing a politician with an ounce of brains regarding problem solving.

 

As it is, politicians are simply your idiot neighbors that have difficulty managing their own lives and soothe their conscience by trying to manage yours.

Edited April 25, 2019 by janice6