Battery cell production at the Tesla Gigafactory in Nevada.
Updated research shows that Tesla batteries may honestly last just about forever.
Nothing lasts forever, but based on new information, a lithium-ion battery pack in a Tesla vehicle could potentially outlast its owner, not to mention the rest of the car, and quadruple the life of an ICE vehicle. The updated study posted on the Dutch-Belgium Tesla forum tracks 900 Tesla drivers around the globe in regards to their battery degradation. It shows that after 521,952 miles (840,000 km) the battery should maintain 80 percent of its original capacity.
According to the U.S. Department of Transportation, the average American drives 13, 476 miles per year. Let's make it easier and significantly overstated and say that we drive about 20,000 miles each year. So, 500,000 miles would take us at least 25 years, although people have been known to rack up many miles in a shorter time period (but it's really rare). Keep in mind this is only taking the battery down to 80 percent. To deplete a Tesla battery completely could truly take more than a lifetime.
The spreadsheet shown below was first drafted by Matteo but is now updated by Maarten Steinbuch (via Teslarati):
Tesla battery degradation chart via Matteo and Steinbuch
As you can see, the spreadsheet simply plots points to signify each owner's remaining battery capacity. Though there are surely some points that are outside of the norm, this makes it easy to see trends. Whether or not you agree with the study, or believe in its validity or scientific merits, it's perhaps the best model out there to give Tesla buyers/owners an idea of battery/range/performance degradation over time.
According to Tesla, the Model 3 will use the automaker's new 2170 cells, which could potentially last even longer than the 18650 cells referenced in the study.
An average ICE car is expected to exceed 100,000 miles. At around 150,000 miles (or less), most ICE cars are deemed "done". Again, there are many exceptions, but the point is valid. Essentially, it loses an average of 1 percent every 30,000 miles. However, according to Steinbuch, at 150,000 miles the average Tesla battery still has about 92 percent of its original capacity.
Following this trend brings him to the conclusion of 20 percent degradation over 500,000+ miles, with 80 percent capacity still available. Hypothetically, a Tesla battery would be "incapacitated" at three million miles, though this could likely never be tested, and you couldn't really use the car regularly once the battery degraded down into the numbers well below 50 percent capacity. It's still an interesting stat, for sure.
It's important to note that this study is based on Tesla's current 18650 battery cells. The Model 3 will use the new 2170 cells, which are more energy dense and efficient. While no study has been performed on the 2170 cells, you can bet that they may last longer than the earlier cells.
Ben Sullins of Teslanomics visited this subject not long ago, prior to the recent research update. Check it out below: