My Battery
Warranty Dispute
with Tesla

February 19, 2022

Model 3 Battery Pack
(Click to enlarge)

Several weeks ago by pure chance I happened to notice that my Model 3 was charging from my Tesla Wall Connector in the garage at only 32A instead of the usual 40A:

A few days later, when I went to retrieve some purchases from the car while it was charging, I also saw this alert on the touchscreen:

This struck me as very odd, so I checked everything I could in our electrical system: the Wall Connector, its 50A breaker, other breakers, our Tesla Powerwalls and Gateway, the electric meter, our solar panels and inverter, the utility webpage for a possible brownout —all to no avail. Nonetheless, the slow charging and alert continued, day after day. I then decided last week to drive my car to our community village and plug into its 48A Destination Chargers. The same slow charging and alert appeared once again! Obviously, whatever the problem, it was inside my Model 3’s Battery and Drive Unit System and could not be blamed on external sources of electricity.

Now that I knew the problem was in the car itself, I set an appointment with the Service Center in Las Vegas where we had taken delivery originally. While en route, I received a message from the service technician saying that I would have to leave the car there for two days, and they would provide me with Uber credits for transportation. To take me back to Utah? No way! When I arrived, and the service advisor realized that I lived out-of-state, she arranged to provide me a rental car from Hertz. I was very fortunate that, after waiting a few minutes at Hertz, another customer turned in a Standard Range Model 3, and I was able to use it to drive back home.

After returning home, I received another message from the service technician. It stated that the problem was in my Model 3’s “High Voltage Battery Service Panel” (commonly referred to as the “penthouse”) of the battery pack. Specifically, the charging hardware in the penthouse (technically called the “Power Conversion System” or PCS) was failing and needed to be replaced. They then claimed that I would have to pay nearly $2K for a replacement, because Tesla won’t cover repairs in the High Voltage Battery Service Panel under its Battery and Drive Unit Warranty. Needless to say, I was in complete shock. It seems more than obvious to me that the penthouse is an integral part of the Battery and Drive Unit System and should be covered in the warranty.

Here is an illustration borrowed from “How a Car Works” showing the Battery and Drive Unit System:

As you can see, the illustration clearly shows that the Battery (skateboard) and Drive Unit (motor) are a fully connected system in the vehicle, and what connects them is the High Voltage Battery Service Panel (the “penthouse”). The penthouse is therefore an essential bridge that binds the Battery and Drive Unit together through yellow cables in the illustration. More specifically, the penthouse feeds, monitors, and regulates electricity from the Battery to the Drive Unit; it also feeds, monitors, and regulates charges to the Battery from AC Wall Connectors, DC Superchargers, and DC regenerative braking sent back from the Drive Unit.

Here is a photo of the PCS inside the penthouse:

Clearly visible toward the middle of the circuit board are three sets of blocks, fuses, capacitors, etc. Each one of those sets converts and delivers 16A of power to the battery, and thus all three combined produce 48A, the maximum amount of AC power that a Model 3 can accept. If one of those sets breaks down, the remaining two can only deliver 32A of power (which is starting to happen in my penthouse). If a second set fails, the last one will only deliver 16A of power (which has happened with other owners experiencing this problem). And if all three sets breakdown… the car cannot be charged at all from a Level 1 or Level 2 charger.

It is only reasonable to conclude, therefore, that the components like the PCS in the penthouse are, in fact, part of the Battery and Drive Unit System. Indeed, what good is a Battery without power channeled through the penthouse from a Wall Charger or the Drive Unit? And what good is a Drive Unit without power channeled through the penthouse from the Battery? To claim that the penthouse is not part of the Battery and Drive Unit System covered under the Battery and Drive Unit Warranty therefore makes no sense whatsoever. Without it, both the Battery and the Drive Unit would be completely useless, unable to function as intended, rendering the battery electric vehicle inoperable. Indeed, it is relevant to note that, when and if a Tesla Service Center replaces the battery in a Model 3, this is what they install:

Therefore, Tesla certainly does consider the penthouse an integral part of the battery. I have never heard of an instance when the technicians merely transfer the penthouse from an old battery skateboard to a new skateboard. They always install the whole kit and caboodle under the Battery and Drive Unit Warranty.

I purport that part of the problem is that Tesla's Battery and Drive Unit Warranty is too nebulous and non-specific. It does not state in concrete terms what components are —and are not— covered:

For example, to justify charging me for the repair, the Service Manager in Las Vegas insisted that “the battery warranty is specific to the battery.” So… what exactly constitutes “the battery”? Only 2170 cells? Not the coolant tubes? The BMS? Cathodes? Cables? Etc., etc.? The fact that Tesla always includes both the skateboard and the High Voltage Battery Service Panel when replacing “the battery” would indicate that it is, in fact, an integral part of… “the battery.”

In the Tesla forums, I have discovered that a growing number of owners are also experiencing the same problem with their vehicles, as you can see in this thread, this thread, this thread, this thread, this thread, this thread, and a thread I started. After so many instances of the problem, I have the impression that Tesla is trying to avoid recognizing that they have manufactured and sold vehicles with substandard battery charging hardware —let alone concede that repairing it should be covered under the Battery and Drive Unit Warranty. Ironically, however, some owners have had the PCS in the penthouse replaced under that warranty! Indeed, that is what this owner reported, and then later even copied-and-pasted what his invoice stated:

Another owner similarly posted an image of the relevant part of his invoice that clearly states that the Service Center replaced it at zero cost with the description “Pay Type: HV Battery Limited Warranty.”

Other owners, like me, have been told that the warranty does not apply, and that we will have to pay for the repair.

I am convinced that Tesla is well aware that they are installing faulty battery PCSs in the penthouse. In fact, Tesla once issued a Technical Service Bulletin about the “HV Battery System,” which states that “For certain Model 3 vehicles, the power conversion system needs replacement." Although the bulletin projects dates for the vehicles possibly affected (the earliest, one month after I took delivery), it does not clarify why those PCSs had a problem. Were they from a different manufacturer, design, material, or build than other PCSs installed before and after those dates? I strongly suspect that, in reality, Tesla has been installing the very same, identical PCSs in the Model 3 for years, both before and after that Service Bulletin, and has failed to inform all Model 3 owners of the potential problem.

This would explain why an increasing number of owners are now finding that this integral part of the Battery and Drive Unit System is starting to fail after 3, 4, 5 years of ownership —in my case after only 3 years and 9 months. It is apparent that these battery PCSs are of poor design and quality, faulty, prone to break down, and Tesla is trying to pass the hefty expense of these failures on to owners by claiming that the components in the High Voltage Battery Service Panel are not part of the Battery and Drive Unit System. I contend that they most certainly are, for the reasons I’ve explained above.

Consequently, I decided to reject the repair cost quoted by the Service Center, and drove back down to Las Vegas the next day to retrieve my Model 3 with its faulty PCS. I have since filed a complaint for arbitration to settle the dispute according to the “Agreement to Arbitrate” clause in my original Purchase Agreement. What I desire is for Tesla to remove and replace the faulty Battery PCS in my Model 3 free-of-charge under the Battery and Drive Unit Warranty. I would also like the company to henceforth do the same for other owners when and if their inadequate PCSs continue to fail. I am convinced that there will be a growing number of such breakdowns in the near future.

To be brutally honest, I find it ironic that, for several years, Tesla has bragged that the maintenance and repair costs for its vehicles are so low that they make their higher purchase prices more affordable than a gas car over a lifetime of ownership. With the Service Center refusing to cover faulty —and expensive!— PCSs under the Battery and Drive Unit Warranty, Tesla's braggadocio about such costs now strikes me disingenuous —if not deceptive. As a Tesla shareholder and a very active EV advocate, I am frankly embarrassed to remember the innumerable times I’ve echoed that claim to hundreds of potential owners when giving speeches, presentations, “Ride&Drive” demos, and displayed my Model 3 at National Drive Electric Weeks, Transportation Expositions, and Earth Days.

I also must say that, now that I know that the Battery PCS in the penthouse is to blame, I deem it disingenous —if not purposely misleading— for Tesla to have programmed that particular alert above to appear on the touchscreen. After all, when the car detects other problems, such as a weak 12V battery, an alert specifically advises the owner to contact a Service Center to replace it. Not so when it detects this particular problem: the diagnostic software tries to point the finger at “poor grid quality” instead.

Finally, I find it disturbing that, in the latest software update 2022.4.5.21, Tesla has changed the charging display so that the volts, amps, mi/hour, etc., are now in a tiny grey font, practically illegible from outside the vehicle. Is it possible that they have purposely made that change so that it will be more difficult for owners to notice that their cars are charging slower than in the past, and thus be unaware that their PCSs are failing…!?!

Whatever happens with my complaint, I intend to report the outcome in the future —and hope that the results are favorable for all Model 3 owners. As I’ve reiterated so many times in these pages, I love my Model 3 more than any car I’ve ever owned. I’m simply not happy with how Tesla is handling this problem with its batteries.

May 10, 2022

Alas… the Power Conversion System in my Model 3 just keeps failing. As of today, it is only charging at 16A from my HPWC in the garage. Obviously, the second module has also died, so only one is now charging, even though 40A are available:

I should point out that the “time remaining” to finish charging is incorrect on the display screen, perhaps because the software assumes all 40A are going into the pack. In reality, the Tesla Valet app shows that it will take more than twice that long to reach my preferred 80% charge:

Coincidentally, just yesterday I filed my dispute with the American Arbitration Association, and sent Tesla copies of the documents I submitted. I sure hope they’ll expedite my request so that we can settle this dispute in the near future. If the last module in the PCS fails, I will no longer be able to charge at home and will have to rely exclusively on Superchargers. I have also filed a complaint with the NHTSA, for I feel it is crucial that Tesla fix this problem not just for me, but for a growing number of owners.