Electric Cars Could Last Much Longer Than You Think - Rather than having a shorter lifespan than internal combustion engines, EV batteries are lasting way longer than expected

From the aricle: "If this 1.8 percent annual degradation continued in a linear fashion, after 10 years an EV would still have 82 percent of its battery capacity, much more than the 70 percent most batteries are warrantied for after eight years."

The battery degradation isn't linear. If the auto makers would themselves believe this, they'd give longer warranties, to encourage sales.