Do you think miles or time degrades the battery more?

Which one is a more useful way to guess how "used up" the battery lifespan is?

Say, a 2015 with just 20,000 miles vs. a 2017 with 50,000 miles? Could the older car be a better bet?

(Of course, as you all taught me, there were some bad batteries in early 2016 that would skew this comparison, so I'm skipping over that year here).

I think use habits play a large role, such as keeping the pack between 20-80% as much as possible, monitoring battery temp, not parking out in the summer sun, minimizing quick-charging on hot days, etc.

It would probably take the 2017 quite a while to degrade to the capacity of the 2015, but I think it's difficult to tell between those examples of age and miles, which would maintain state-of-health the longest.

the 2017 car will have a 30kwh battery with 8 year warranty, the 2015 will have a 24kwh battery with 5 year warranty. 2017 will be a better bet no matter what, because you will get a new battery for 5 more years from now if it degrades enough, whereas the 2015 car will have its warranty expire this year.

to answer your question, miles seem to matter less than time. more miles over less miles in the same amount of time will wear the battery out more, but ultimately time (and more specifically temperature/usage/storage patterns) wears it out most.

Thank you! I know the specifics will really outweigh everything else, but I'm trying to work with the information I can get access to. and of course, I can use LeafSpy to help but only if I make the trek out in person, which is pretty far in some cases.

The 2011-4/2013 batteries degraded over time. Starting with the April 2013 through 2014 "Wolf Packs," time became much less a factor. The issues with the 2016-2017 (yes, both years) 'Lettuce Packs' seem to be related more to manufacturing and/or chemical defects than to time.