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What is Tesla trying to hide about its Powerwall?

I have great respect for a person who pushes boundaries and engages in future-vision projects. We currently lack the great visionaries of the past who established our nations great growth in technology and commerce.

That said, I have no respect or love for someone who toys with great ideas in order to build up consumer and investor hopes for personal profit while remaining silent on the issues that may eventually kill the great idea.

Enter Elon Musk.

I have expressed my reservations about his idea to build a space program to go to Mars, and I have additional reservations about his Falcon Heavy booster that is scheduled to launch sometime later this month.

But it is Tesla’s ‘Powerwall‘ product that has gaping issues that seem to be ignored in all the hype and mystic of Elon Musk. Two issues have to do with lithium-type batteries and their limitations and dangers.

Fantasy Cycles?
Tesla has a ten-year warranty on their Powerwall system. That sounds great, but it is the same as saying if you leave raw fish on the counter at room temperature it will be safe to eat in a year.

There are rules in chemistry. Batteries are defined by these rules. Every battery has a limited lifespan even if it is not used. Batteries also have a limit to the number of discharge/charge cycles it can undergo before they are no longer effective in holding a charge.

Lithium-ion batteries are superior to other types of batteries because they hold more charge per kilogram and they can be recharged. This makes them a good choice for a home power application.

However, lithium-ion batteries begin to deteriorate the moment they have been built. They lose about 5% of their charge capacity per month, and even if they are never used the lifespan of a typical lithium-ion battery is two years.

According to one source, lithium-ion batteries in the Powerwall are limited to between 800 to 1000 discharge/charge cycles. Assuming the Powerwall undergoes only one cycle per day, its useful lifespan is less than three years. Considering that with both normal use, and the natural deterioration of the batteries in the Powerwall, it will fail in less than two years.

But they’re under warranty for ten years, so who cares?

The chemical limitations of the lithium-ion battery are a fact. If Tesla strategy is to deal with massive warranty claims, then both investors and customers should be made aware. If Tesla has come up with some miracle technology they need to explain how they have overcome the chemical limitations.

The danger is that Tesla is aware of the limitations and is preparing for an alternative strategy such as bankruptcy in three or four years after they have squeezed the profits out of the company. Without further explanation, an alternate business strategy is the most likely scenario.

Burn Baby Burn
There is a reason that the FAA required a ban on the Samsung Galaxy Note 7 tablets on commercial flights. Bad lithium-ion batteries.

Lithium-ion batteries can overheat and burn or explode under certain conditions. If punctured they can burst into a fire that cannot be stopped by normal fire suppression tactics. The only way to prevent a lithium-ion fire from doing severe damage to the materials around it is to have a non-burnable barrier that can withstand the heat of a lithium fire.

The Powerwall encased in a metal, temperature-regulated, weather-proof housing. To my knowledge, there have been two tests performed on the Powerwall and its casing. Both tests were performed by a trade organization known as the National Fire Protection Association (NFPA.) The NFPA is not a government, nor regulatory agency, and no information was found as regarding Tesla’s involvement in the design or limitations of the test.

One test performed a test of overheating one cell group to the point of failure. The fire did not spread to the other cells. The second test applied a steady flame to the exterior of the Powerwall. In that test, all cells overheated and failed, but the Powerwall did not explode, nor did the internal lithium fire breach the casing; however, the Powerwall was not mounted on, nor near any combustible material.

The Powerwall does include a system of heating and cooling to keep the batteries within the range required to prevent failure leading to a fire; however, I cannot find any test of a complete cooling system failure in a hot environment, other than the controlled test done by Tesla and the National Fire Protection Association (NFPA.)

I cannot find any testing as to the result of a puncture to the Powerwall. YouTube offers many videos on what happens when a lithium-ion battery is punctured. A puncture test of the Powerwall has not been released to the public, to my knowledge. 

If the Powerwall does not have extensive testing in various environmental situations then it may be impossible to know how dangerous the Powerwall is to mount on or near a wall that is combustible.

To my knowledge, Tesla is silent on this issue. On their website, I can find no information as to these issues about lithium-ion batteries or the safety testing done on the Powerwall casing.

In fact, Telsa is extraordinary reactive to journalists and media. In 2015, Tesla security guards used their ATV to reportedly ram a vehicle with journalists from the Reno Gazette-Journal, smashed their vehicle window, and cut their seatbelt to remove them, throwing them to the ground.

The journalists were taking pictures of the Tesla Powerwall plant under construction in Nevada. According to the newspaper’s attorney, Tesla security guards demanded the camera equipment and held the journalists against their will, created an alternate story that the journalist attacked them, and held them until the sheriff’s department arrived.

Image of inside of Reno Gazette-Journal’s vehicle after encounter with Tesla security guard

The incident suggests that Tesla is extremely sensitive to any unmonitored, unbiased release of information about its Powerwall product. The question remains: Why?