| ▲ | starwatch 2 days ago | |
> That's statistical. A small number will start their exponential degrade at 80%, but most won't. Some might get to 60% before they start it. The paper that underpins the 80% claim is paywalled and I'm cheap so don't have the numbers to hand. But in the abstract sense being statistical could go the other way too - i.e. some might get to 90% before they start their exponential decay. > And "exponential degrade" doesn't mean it's particularly fast. True, exponential doesn't mean much other than e^n where it's implied that n > 1. However the value of n does matter, for example a decay rate for n=100 is quite different than n=1.1. Again, we're talking in general terms as I don't have the value of n for this. For better or worse, I'm taking the paper at face value when it talks of end of life at 80% - however it has been peer reviewed and is in a "proper" journal so to my mind that adds some credibility. It's worth mentioning that the current DoE guidance on lifetimes is: "12 to 15 years in moderate climates (8 to 12 years in extreme climates)". Of course that guidance is also based on a statistical analysis that doesn't seem to account for modern battery management systems [1]. There are additional factors at play that govern battery degradation, including things like: battery chemistry, environment, EV charging habits, etc. Ultimately the real test of EV battery life will come with time. It'll manifest as the change in average age of scrapped vehicles with large fleets of EV's on the road. In Norway right now it's about 18 years (for a mostly internal combustion fleet) [2]. However as of this year all private vehicles sold must be zero-emission - so in 10-20 years we'll have some interesting data [3]. [1]: https://web.archive.org/web/20250530000446/https://afdc.ener... [2]: https://www.ssb.no/en/statbank/table/05522/tableViewLayout1/... [3]: https://web.archive.org/web/20250530115356/https://www.regje... | ||
| ▲ | starwatch 2 days ago | parent [-] | |
Edit: It'll manifest as the change in average age of scrapped vehicles [in countries] with large fleets of EV's on the road. | ||