Don't we already have a lot of real-world data on this from plug-in hybrids over the years? The use conditions are quite different of course, but it should still give a realistic expectation for how they age over time.

The rhythms of real-world driving enable EV batteries to live far beyond the predictions of laboratory tests, according to a new study from Stanford University. Thereport, published in December inNature Energy, suggests that EV batteries could last 38 percent longer than previous lab-based estimates. That means drivers could get as much as 314,000 kilometers (195,000 miles) more out of their EVs than academic researchers believed.