The longevity of batteries has always been an area of concern for EV buyers, with the very early models featuring very poor battery management which left them with a crippling high rate of capacity reductions over time.
Tesla uses sophisticated battery management techniques, including active temperate management and preconditioning, to ensure their batteries last a long time, but there is still inevitable degradation over time.
To reassure buyers Tesla has been offering an 8 year or 150,000-mile warranty on the battery of their high-end models. Today Tesla has updated that warranty to make its failure conditions a bit more explicit.
The page on Tesla’s website now notes:
The Battery and Drive Unit in your vehicle are covered for a period of:
- Model S and Model X – 8 years or 150,000 miles, whichever comes first, with minimum 70% retention of Battery capacity over the warranty period (with the exception of the original 60 kWh battery manufactured before 2015, which is covered for a period of 8 years or 150,000 miles , whichever comes first).
- Model 3 and Model Y Standard or Standard Range Plus – 8 years or 100,000 miles, whichever comes first, with minimum 70% retention of Battery capacity over the warranty period.
- Model 3 and Model Y Long Range or Performance – 8 years or 120,000 miles, whichever comes first, with minimum 70% retention of Battery capacity over the warranty period.
The warranty now notes at least 30% battery capacity degradation is allowed over an 8 year period before the warranty would kick in. The 70% capacity level requirement was already in place for the Model 3. The update only applies on new sales and is not retroactive.
With Tesla working on a million-mile battery some have expected Tesla to increase their warranty, but of course, in practice we know 30% capacity loss is already unusual over this span, with many veteran users will having over 90% battery capacity. The move may have been related to increasingly common commercial use of Teslas in ride-sharing and other applications, which may stress the system more than usual.
Tesla is due to hold a battery day some time in March, where they will be talking about its next-generation battery technology, which is expected to increase the already large gap between Tesla and other car companies, who’s EV efforts have generally fallen short of expectations.