alt Hacker NewsAlthough the thought of getting an electric car has passed through my mind on a few occasions, I'm not 100% familiar with the intricate technical details. (for some reason, the tax incentives where I live are still in favor of continuing with the small petrol car I have. Taxes are primarily a function of weight in the Netherlands, and anything besides a lightweight Dacia Spring would imply significantly higher monthly expenditure for me).
What I'm wondering w.r.t. this article is: wouldn't such fast charging shorten the battery lifespan?
I have experience with ebike batteries. Bosch in particular, with very decent 29E samsung cells, that after 70k km or so, basically halved their capacity. I imagine this effect is severily reduced with a car battery because there are a lot more than 10p, so all the wear is distributed more evenly, and 29E are very old technology.
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Rule of thumb for modern EVs is to not care about the battery at all. They are expected to last longer than the car. I would doubt even faster charging significantly changes this, or if it does it’s worth the trade off to those who need it.
I believe you meant to write “10S” instead of 10p. I’m not 100% sure, but you were talking about e-bike batteries, which are often 36V, made out of 10 cells (or banks of cells) in series. The nominal voltage of most lithium chemistries is 3.6-3.7V.
EV batteries have many more cells in series, for example my car is 104S, and 800V cars have (obviously) more than 200 cells in series.
And the longevity of car batteries isn’t about wear being distributed “evenly” (a healthy battery can’t really wear “unevenly”, you always load all cells at once). EVs take care of their batteries, they cool them, heat them, balance them periodically, and they don’t actually pull that much power from them. They also keep the cells within pretty conservative voltage limits.
Research on the current EVs shows that they degrade by on average 2.3 % of original capacity a year, but there is a strong dependency on how much the vehicle is used and how often it is DC fast charged, i.e. there is time based degradation and usage based degradation.
Low use vehicles have degradation of 1.5 % a year, heavily used vehicles mostly slow charged had degradation of 2.2 % a year and heavily used vehicles mostly fast charged had highest degradation of 3 % a year.
Now before you think that means the capacity will halve in X years (33, 23 and 17), the article also notes that the degradation is not linear and it was faster in new vehicles and then slowed down - with no way to know if it will slow down further or continue in this manner, etc, until we have a sufficient sample of 20 years old modern EVs.
Link to article https://www.geotab.com/blog/ev-battery-health/