Tesla Model S Owner Accuses EV Maker of Hiding Design Flaw in Battery Packs

Failing Model S battery packs are nothing new, but Zelaya’s case may shed some light on the problem. In December 2021, Tuomas Katainen had only driven his used 2013 Model S for 1,500 km (932 mi) when error codes emerged. The diagnostic he received was the same as Zelaya’s: a damaged battery pack, which would need a €20,000 replacement – $19,934 at the current exchange rate. Katainen decided to explode his electric sedan instead, which is something the Canadian Model S owner considered until he found a final solution for his situation.

We have no idea what went wrong with Katainen’s car, but another case may confirm Zelaya’s concerns. On October 8, 2021, Larry Campbell’s wife tried to pick up their kids at school in Hong Kong with the family’s Model S, but it stopped working. The Tesla Service Center told him he would have to spend HK$171,000 ($21,785) to replace the battery pack, which is under warranty until 2024.

Tesla claimed that the “car was flooded,” but Campbell said that never happened. He should know about that: the EV parks in his garage since he bought it new in September 2016. So what could have caused the battery pack to seem flooded? You’ll soon understand how these two stories connect.

Zelaya’s TikTok video about the issues in his EV went viral, and we contacted him to understand everything that led him to believe Tesla was hiding issues with the Model S battery pack. According to the Tesla customer, the situation started when he got a high-voltage problem alert while driving his electric sedan to work in Burlington, Canada.

After getting the warning, Zelaya made it to the closest Tesla Service Center and left his Model S there. He was surprised by the first diagnostic he received. “They were originally telling me that they needed to replace the AC unit and possibly the drive unit, but that wouldn't guarantee it would fix things. They basically wanted me to spend CAD10,000 to ‘hopefully’ fix the problem.” Zelaya said he had spent CAD20,000 ($15,054) repairing his vehicle since he purchased it for CAD141,852.10 ($106,772.08) on June 19, 2012.

The Model S owner doubted Tesla’s explanation. “I pushed back on them and mentioned that they replaced my drive unit 3 or 4 years from when I first bought the car. That couldn't be the issue; it had to be something else.”

Problems with the electric sedan’s drive unit (DU) are famous. Hansjörg Eberhard von Gemmingen replaced them “11 or 12 times” in his 1-million-mile Model S. Despite that, the Tesla Service Center must have agreed it should dig deeper into what had happened to Zelaya’s car after he “pressed them on this and reiterated how ridiculous it was to charge” him “that much money to replace things that may not need replacements.”

On March 14, he received the CAD28,684.83 bill for a 90-kWh battery pack. That’s equivalent to $21,597.58 at the current exchange rate. Curiously, Autotrader and KBB do not have prices for used Model S units before 2019 in Canada. Tesla opened its first store in that country in November 2012.

Just for us to have an idea of how much such a car is worth, KBB states a 2013 Model S Performance sells for around $37,000 in Detroit. If any Model S owner received a similar invoice for a new battery pack, the component would represent 58.4% of the car value. That would mean a total loss should the battery pack fail for something an insurance policy would cover.

With the estimate, Zelaya also received an explanation for having to replace the battery pack in his car. Although the warranty ended in 2021 – eight years after purchase – the vehicle was still far from the 150,000 miles Tesla’s warranty covers in more recent Model S units. It was not a matter of external damage or wear: the battery pack was filled with water. Campbell may have heard that his “car was flooded” for the same reason. The main difference is that the Canadian Tesla Service Center was candid about the problem.

“They said that this piece that protects the battery pack rusted, and that's how water got inside. The technician who confirmed that at Tesla said: ‘It smells like a lake in there,’” Zelaya told autoevolution. That led the Tesla Service Center in Oakville to try to get their “head office/Canada Director” to approve Zelaya for “a free battery replacement – mainly because the water issue was because something had corroded on top of the battery pack.”

Transport Canada later helped to name the “piece that protects the battery pack” Zelaya mentioned. We’ll get there in a bit: the Model S owner heard more from the Tesla technician before the Canadian transportation department got involved.

“The issue would have started when the battery was under warranty, but Tesla never checks batteries – even though I did all my checkups and service with them,” Zelaya said. “They told me that they can't detect when water is in the battery pack. So it could have started two years ago when the car was under warranty.”

With the corrosion diagnostic, the battery pack damage definitely took a while to develop. That’s why the Tesla Service Center tried to replace the battery pack under warranty. The issue is that the request was denied. On March 28, Tesla sent Zelaya an email saying he could take his car back if he signed a document stating he did not want to replace the battery pack. The Model S owner declined to sign anything: he feared “it would excuse them from liability for something they knew was an issue but refused to fix.”

“Since it was outside of the warranty period, they refused to cover the battery pack, which is ridiculous. They know they have issues with their cars, with their batteries, but they never check them during maintenance, which could have identified the issue early on.”

For Zelaya, that was not due to incompetence or negligence: he thinks it was on purpose. The Model S owner believes Tesla “designed the battery packs so (that) they don't have to know the issues” to avoid replacing “the most expensive part of the car, even if there's an issue with it.”

“They said they did get some initial high-voltage (problem) alert sent to Tesla HQ, but not to the end user (to me). So they alert themselves of the issue, but never the driver. They make it so (that) they have deniability when a fire occurs.” Furious, Zelaya decided to contact Transport Canada.

The Canadian transportation department went to the Tesla Service Center to check the vehicle and the battery pack. Zelaya sent us the report Transport Canada produced. It shows that the AC condensate drain hose sits right over the battery pack. According to the document, “in this arrangement, its contents will drain on top of the battery case behind the No stain marks below area.” It seems that this is precisely what happened with Zelaya’s EV.

On the same page of the report, we can see the part of the chassis with the stains and also an area with corrosion deposits. The water that leaked from the AC drain hose over the battery pack made the high-voltage (HV) battery pack main fuse cover rust. This is the “piece that protects the battery pack” that Zelaya talked about.

When the fuse box steel cover rusted, water entered the compartment and invaded the battery pack. It is not clear if that water damaged the cells, but it must have caused an issue to trigger the high voltage alert Zelaya received.

When Transport Canada checked the battery pack, it noted that the “HV Battery main fuse area (was) showing a replacement metal cover with edges under waterproofing goop. Dealer discarded the original cover.” To Zelaya, the Canadian department inspector said there was “nothing he could do, but it was very suspicious that they (Tesla) would do that.”

We contacted Transport Canada and asked if it decided that issue was enough to order a recall for the fuse box cover. According to the Canadian department, it “has only received one complaint relating to an issue of battery corrosion with a Tesla model vehicle.” It did not confirm it was Zelaya “due to privacy legislation,” but it is clear that this was the case. Zelaya was happy with them anyway.

“Transport Canada was great. They had Tesla leave the battery pack out to dry. Tesla had the car for over six or seven weeks. My range was obviously affected by all this. It functioned again. The big issue that I had was that Tesla interfered with the investigation and changed a part that I didn't sign off on – Tesla never repairs or does work on a car unless you have a signature from the customer – to cover up the rusted piece.”

You read it right: after the battery pack dried, Zelaya started the vehicle and kept on driving it as if it had nothing wrong until he shot the first TikTok video on August 31. That was when the car started failing again. We asked him if Tesla had discussed anything with him after he posted his videos or warned him about the risks of using the vehicle. He said that was not the case but that his car started getting low-voltage alerts. That’s an indication of 12V issues, something the Model S is also famous for presenting. Zelaya thought Tesla had blocked his vehicle remotely.

With his case, we now have another possible cause for battery pack failures and fires: water entering the battery pack after the AC drain hose drops it on top of the HV component. Zelaya said that Tesla fixed the problem in 2015 units, but Campbell’s Model S is a 2016 vehicle. It would be interesting to know if the AC drain hose is still in the same place in newer cars.

If that is the case, the company may have fixed the issue without warning its customers about it. If it didn’t, it should place the drain hose in another location, which is easier to service and verify. It could also add some sort of protection to the battery pack in that area or make a fuse box cover from a material that is not subject to rusting.

Although the situation he faced could be isolated, Zelaya said he knows other customers that have had the same issue as he did. We will try to learn their stories and discover if the rusted fuse box cover happened in more cases. If you are among them or know someone who is, please let us know.

Zelaya’s story with Tesla ended with him selling his car to someone who needed its parts. This person apparently appears in one of his TitkTok videos removing the nose cone and charging the 12V battery. The buyer may also try to fix the EV with the 057 Technology, The Electrified Garage, or other Tesla specialists. Apart from the battery pack issue, it seems to be in good shape.

It is important to mention that this battery pack problem is different from what Business Insider reported on June 24, 2020. In that case, the components allegedly had a defective cooling system that allowed coolant to leak. Business Insider said that the dried coolant was flammable, something that Jason Hughes – the Tesla Hacker – debunked at the time.

Besides these two possibilities for battery pack failures, Tesla has never explained why it decided to cap the voltage of the Model S and Model X battery packs with an over-the-air (OTA) update a few weeks after a Model S caught fire in Shanghai in 2019.

When American customers sued the company accusing it of capping the voltage to conceal issues with the battery pack, Tesla made a deal to end the lawsuit. Elon Musk even said the company’s policy was “never to fight true claims, even if we would win.” That depends on the country: while Tesla settled the case in the U.S., it is still fighting Norwegian customers with the same complaint. They won their lawsuit against Tesla, and the company appealed the decision.

@supermariozelaya Replying to @RamblinB Definitely lucky it didn’t go up in flames based on how they designed their cars. A recall is needed. #tesla #car ? original sound - Mario Zelaya

@supermariozelaya Replying to @richard_kierstead I can’t wait to blow up my Tesla. Trying to find legit way to do it in Canada. #tesla #lemon #car ? original sound - Mario Zelaya

@supermariozelaya Replying to @mstar611 Did I forget to mention how they interfered with a Transport Canada investigation and made unauthorized repairs on my car to bury proof of the issue? #tesla #car #viral #fyp #canada ? original sound - Mario Zelaya

@supermariozelaya Replying to @NoMoreBoobSweat I couldn’t agree more. People need to wake up. I got contacted by someone suing Tesla for an almost identical problem to mine. I’m going to see if I can help them in their court case. Looking back, I would have had an extra $3mm if I bought the stock instead of the car. ???? #tesla #car ? original sound - Mario Zelaya