understanding tesla\'s life threatening battery decisions

In the past few months, Tesla Motor\'s electric vehicles (NASDAQ:TSLA)
Three collisions.
The battery fire was widely reported in the media.
Last week, NHTSA decided to conduct an official investigation into the incidents.
While Tesla CEO Elon Musk is on an immediate offensive, he believes that Tesla\'s BEVs are less risky than a gasoline-powered car, but more and more investors are asking the question, \"Why did Tesla have three battery fires in a fleet of 17,000 BEVs, while Nissan did not have any fires in a fleet of more than 90,000 BEVs?
The answer is simple.
Tesla\'s battery decision significantly increases the battery risk for customers and companies.
The main resource I discussed in this article is a 2012 study published by the National Renewable Energy Laboratory called the vehicle battery safety Roadmap guide.
\"Since the roadmap provides more scientific details than most investors need or want, I will focus on general topics that affect investment risk and leave electrochemical and engineering details for professionals.
\"Lithium-
\"Ion battery\" includes at least half
More than a dozen varieties, from relatively safe iron phosphate preparations to relatively unstable cobalt oxide preparations.
I use this word because there is no lithium.
100% safe ion battery. All lithium-
If the battery is punctured, the ion battery will burn.
Generally speaking, the fire caused by the punctured cell is the least violent. Lithium-
If the pieces left over during the manufacturing process penetrate 15-to 25-
Micron separator and generate internal short circuit.
In these cases known as \"field failure events\", the internal short circuit ignites the material inside the battery and causes the internal temperature to soar to several hundred degrees Celsius in a few seconds.
At this point, the cells burst, providing additional oxygen to the fire.
In rare unexplained cases, the internal temperature will soar to several thousand degrees Celsius in a few seconds, indicating that an aluminum heat agent reaction may occur.
Failure Mechanism of lithium
The ion battery is not well understood as it is almost impossible to extinguish lithium
Ion battery fire
What the best first responders can do if a fire occurs is to try to cool the surrounding packaging to prevent the fire from spreading.
All we know is that the cells that are pierced are less responsive than those with magnetic fields.
Failure events and on-site failure events are less violent than other failures that some experts attribute to the aluminum heat agent reaction.
Thermal energy released by burning lithium
Ion batteries are three times higher than the electrical energy released by the battery in the normal discharge cycle, and as the temperature increases in one cell spread to adjacent cells, causing them to enter the heat out of control, cell puncture and field failure events can be a very important thing.
This phenomenon is like lighting one side of the Matchbox.
Once the first one is gone, others will definitely follow.
A recent Tesla fire on the Yucatan Peninsula in Mexico was filmed in a YouTube video showing the process of lithium.
The ion battery unfolds in a large battery pack.
The video starts with a moderate fire in several pierced battery modules.
As the temperature rises, other modules reach the point of Heat runaway and explode.
In the finale, several modules join the party and explode at the same time.
If the incident does not involve a $100,000 car and a real-life accident, it will be a huge special effect for Hollywood.
Tesla\'s first adventure battery choice is to pick batteries with high energy density and unsatisfactory safety, rather than batteries with low energy density selected by all other automakers.
Its second adventure battery option is to ignore the law of large numbers. Field-
Fault events are very rare, and while I have not yet found detailed statistics on the 18650 batteries Tesla purchased from Panasonic, the NREL report states that the battery pack in the Tesla Model S uses about 7,000 high
The energy of the easier field is 18650 cells-
More secure lithium failure eventIon Chemistry.
Since each battery in the battery pack represents an independent risk of field failure, the risk of catastrophic field failure events at the battery pack level is: some of the more disturbing aspects of the NREL report include the observation: batteries in electric vehicles remain in high-charge condition to maximize the range of travel.
Unfortunately, this approach also maximizes the likelihood of failure events on site.
Since Tesla wants its car to have the longest mileage possible with the lowest possible battery weight, it has chosen a relatively unstable high
Energy battery chemistry, while competitors of electric vehicles with shorter production ranges choose safer and more stable chemistry.
As Tesla wants to keep its battery costs low and take advantage of the overcapacity of 18650 batteries worldwide, it has decided to use 7,000 small batteries in its battery pack, more experienced car manufacturers pay high prices for large car-grade batteries, which reduces the impact of the law of large numbers.
All of Tesla\'s public talk points about the three fires are focused on the collision --
Related Properties of battery pack failures.
Statistics in the NREL report show that if Tesla uses a safer low package, the catastrophic package failure rate of 1 out of 6,000 is almost correct
Energy Chemistry like lithium iron phosphate.
If NHTSA concludes that the fire is due to Tesla\'s adventure of choosing a high energy density battery in 7,000 battery packs instead of road debris, the impact on Tesla will be life-threatening.
In my opinion, the current market price of Tesla\'s common stock does not reflect this real and substantial short term
Risk of long-term survival
Disclosure: I do not have a position in any of the stocks mentioned, nor do I have a plan to start any position in the next 72 hours.
This article was written by myself and expressed my views.
I received no compensation (
In addition to Seeking Alpha).
I have no business relationship with any stock company mentioned in this article.
Supplementary disclosure: I am a former director of Axion Power International and hold a large number of long-term positions in its common stock.
I am currently acting as executive vice president of ePower Engine Systems, a private holding company that is developing engines
The leading series of hybrid transmission systems for heavy trucks.