Pete Gruber and his team at Gruber Motor Company started an analysis on how Tesla vehicles age. Beginning with the Roadster and going to the Model S, Gruber came to very enlightening conclusions, some of which we have been warning for quite a while. The first and most interesting one is that Tesla pushed prototypes into the field as if they were production vehicles.
It sounded absurd when a company supporter said he accepted the fact that the Model 3 was still a prototype in an attempt to exempt Tesla from the flaws it presented. Yet, Gruber indirectly gave that company backer some reason, at least in what relates to the Roadster.
The engineer even named a few examples that base his conclusion. The side scoops were meant to keep the power electronics module cooled, but it did not work. To fix that, Tesla installed a 12V DC fan anywhere it could fit. That ended up being behind the rear wheels, in a very low position, where it picks up “dirt, dust, leaves, and debris.” The practical result is the need to clean the power electronics module every year.
Another piece of evidence that the design needed to be more mature before customers could get delivery of the cars was that a high number of wear-related components such as fuses on circuit boards and inside the DC-to-DC converter, and contactors on both sides of the .
Gruber argues that these components should have been placed on top of the battery pack, in a position that could be reached even from inside the car. To replace these wear components, it is necessary to remove the Roadster battery pack, an operation that requires the rear suspension to be disassembled and takes a day to complete. At least fuses and contactors are not an MCU, a component we would never expect to be a wear part.
In Tesla’s defense, Gruber remembers that early Ferrari units were also prototypes. That did not prevent them from being some of the most valuable classic cars around. Gruber also stresses that the battery pack was created to be safe and reliable.
Its firmware and battery management were what allowed the multi-cell design Martin Eberhard, and Marc Tarpenning developed to set the foundations for modern electric cars. It has liquid cooling, moisture detectors to prevent leaks, and a self-explanatory smoke detector.
Gruber highlights that, despite the rush in delivering the Roadster, it still sold for less than it cost to produce, something that jeopardized Tesla’s existence at the time. This seems to be one of the main reasons alleged by Elon Musk to oust Eberhard from the company.
Gruber then asks how long Tesla battery packs will last. Although there is not enough time to determine that yet, Roadster battery packs were expected to last 10 years, and some already count 13 years with no issues. The cells that fail are qualified by Gruber as “aberrations.”
Despite that, the engineer fears “massive daisy chain failures” will eventually occur, first with the Roadster and then with the Model S. That will mean the repairs Gruber Motor Company performs will no longer be possible.
The company currently isolates defective cells in the circuit so that the others can work again. From the required amount of work required to do that, it charged $5,000. The guys from Cleevely Motors Ltd. teased Gruber in a recent tweet.
Cleevely recently made a repair in a Nissan Leaf battery pack that presented how the air-cooling strategy for EVs was wrong. It also made us wonder if just replacing the battery module with the parasitic cell would not be cheaper.
We’ll ask Gruber about that and if there is any disadvantage to that approach. However, the example given by Cleevely puts it on the same side as Gruber Motor Company: trying to keep EVs running as much as possible.
Gruber mentioned the Toyota Prius case as an example of what can happen. According to him, $6,000 used Prius units are being sold for $500 because their main battery packs have failed and they cost $5,500 to replace.
That’s also the story behind a Model S that one Gruber customer bought for $10,000 and that ended up costing him $15,000 due to the $5,000 repair performed at the shop. Considering a Model S battery pack sells for $20,000 to $22,000 and a used Model S costs around $25,000, these used cars are at risk of just being delivered to junkyards, which would be a real pity.
Without emission concerns, electric cars in good shape could drive for thousands of miles if they had economically feasible solutions to replace defective or worn-out battery packs. Remanufactured, recycled, with bad modules or cells replaced: you name it. The owners will just want to keep them running, as we have shown multiple times with Nissan Leaf drivers.
This is a pressing issue for all the electric car manufacturers, including Tesla. Suggesting that affected customers just buy a new car when all that is not working well is the battery pack can taint EV reputation in the long run. Let’s hope they all have that in mind.