Last April, a Tesla Model S burst into flames in Shanghai. By the end of June, Tesla released the results of their analysis on the accident and announced an update to improve the battery pack's lifespan. Since May, many owners of vehicles with the same battery pack – already discontinued – have been complaining about recharging times. And of less range. These events could be totally unrelated, but it seems are closely tied.

According to the Norwegian website Tek.no, Cato Standal left his Model S P85 in a Tesla shop a little before Easter (April 21) to have something in its steering system fixed. After getting the car, he had to take it back for another repair.

Standal thought it was something with the painting, but, after four weeks, he sent the shop an email and discovered the car's battery pack had error messages. Two more weeks passed before he could get his Model S back.

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That was when he discovered the whole battery pack had been replaced by a new one. But it was a smaller one, with 67 kWh instead of 85 kWh. Strangely, the number series of the battery pack indicated it had an 85 kWh capacity, even if this pack is not offered since 2016.

That is one of the pieces of evidence that led Standal to believe the restriction is software-based. But not the strongest one.

“What makes me be 100 percent certain that this is a software limitation is that now I have full regeneration even if the battery is fully charged. That has never happened before,” Standal told Tek.no. “If the battery was 100 percent charged, you would not get more power.”

The fact is that Standal’s battery replacement case is not the only one. Tek.no says there were others in Norway, the market with the biggest EV share in the world – 57.8 percent of all cars sold in June. But those are only the most extreme cases.

Other Tesla owners report that, after the software updates 2019.16.1 or 2019.16.2, the range of their cars fell around 10 percent. When it is not shorter, it takes much more time to recharge.

“Charging speed has been significantly reduced. And it gets worse in Superchargers, at a State of Charge superior to 70 percent. It can take 30 to 45 minutes more than it used to take,” Richard Lopes, a Portuguese owner of a Model S 85, told us.

Threads on Tesla forums on the problem spread by the dozens since May 13, as an article from Electrek shows. David Rasmussen has been making a detailed report on the battery pack capacity of his Model S and his graphic shows a steep decrease all of a sudden.

On June 3, the user Dutchmeeuw started a thread on the Tesla Motors Club community that is called “Sudden Loss Of Range With 2019.16.x Software”. It is currently on its 86th page. And counting. A clear demonstration that the problem is affecting a lot of people.

Tesla is telling most of them that this is a natural degradation of the battery pack, but its clients are not buying that. And some are so mad that the automaker changed the car’s specs without asking that they are threatening to sue the company.

The main point is that the decrease in range and the time for charging are very noticeable. With the internet, lots of car communities have formed and Tesla’s are one with the most loyal followers. So Tesla may speak to each of them with an excuse, but they will talk to each other. And have doubts about what they are being told.

The user Trayloader, from Germany, suspects the problem has to do with “pre-FL (old chemistry)”. And complains about the persistence of the update, very different from previous ones.

In the end, he presents a graphic of battery degradation that is pretty similar to the one presented by Rasmussen.

The forums confirm the issue is as widespread as Tek.no reports. The Norwegian website states the problem affects mostly P85D Model S and Model X units, but also cars with 60 kWh, 70 kWh, and 90 kWh battery packs. So it is something that may have started with the Model S, but that may affect other Tesla cars.

Tek.no has tried to contact Tesla in Norway, but Tesla’s communications manager in the country, Even Sandvold Roland, declined to comment if the updates, battery replacements and slower charging times have anything to do with the Shanghai Tesla incident.

One thing is certain: having nothing to declare is most of the times seen not as a denial, but as tacit confirmation.

Can Tesla be saving time to prepare a convincing answer to all those affected drivers? Is it trying to hide a battery problem that could demand a massive recall in a very inconvenient moment? Is the update a way to avoid having to replace too many batteries that can have the same problem the Model S had in Shanghai in April?

Tesla's answer

We have contacted Tesla and the company claims very few owners of older Model S and Model X have been affected by what it considers to be a small reduction in the range that followed the software update released in June.

Tesla does not address the incident in Shanghai as connected to the update, but it says it aims to protect the battery and improve its longevity. Anyway, it has also promised to improve the impact on the range for these vehicles.

We are not sure if the owners involved will be satisfied with the reply. Especially with this persistent and unaddressed doubt: is the update a way to prevent new fires such as the one that happened in Shanghai?

If it is, it makes sense to have a slower but safer charging and perhaps losing a few miles of range will not look that bad. If it is not, people will want fast charging and miles of range back as soon as possible.

The EV carmaker is one of the few that could be really candid about what happened and still get support from buyers. They all know it is bravely facing Titans and that it still has a long way to feel completely safe in the market. Probably very few would demand compensation if that was a threat to Tesla's survival.

As Lopes told us, “the lack of answers worsens a perfectly avoidable situation.” Incomplete ones tend not to help as well.

We are readily available for any new comment Tesla may want to make. And also from our affected readers. We suspect this story will still have interesting developments and hope for (welcome) updates.

Sources: Tek.no, Tesla Motors Club and Electrek