EV charging cycles
“Charging cycles”—here is a term you don’t hear much in relation to electric cars, even though it is often the bar by which iPhones and MacBooks are measured on the second-hand market, as it’s always been a value Apple devices keep track of.
Cue ACC, the Stellantis gigafactory partnership with Total. Their mention of charge cycles took me by surprise in their “EV Batteries for Dummies“ slide; they mentioned a 2,000-cycle max and correlated that to a half-million-mile vehicle life. Props to them for that.
Back to the number itself: unfortunately, it’s not that straightforward with cars, as none (AFAIK) store an actual battery cycle number. All we can do is estimate it based on the mileage and real-world range of the car.
For the electric cars I own, that number ranges from 500 charge cycles on my 2015 Mercedes B250e to just 50 cycles on the newish 2021 DS 3 E-TENSE.
Based on this, I can estimate, with the same usage, how many years it will take until the battery goes below 70% of its manufactured capacity. I am going to use the lower 1,500-cycle bar; that gives me a total of 15 years on the old Mercedes/Tesla Frankenstein and a surprising 30-year figure for the Stellantis DS 3.
I do not plan to go into more technicalities beyond that. If you are interested in a more in-depth article, one is available at Battery University.
What I do want to do is share the cycle values for the things I have owned so far and how I found them to correlate to real-world usage:
As for my experience with how the values above correlate to real life: well, the iPhone with 250% max charge cycles is totally usable, and I still use it as much as the newer iPhone. The MacBook with only 50% of the cycles, however, barely lasts an hour or two, so it’s not really feasible to use it with no charger nearby. As for the B250e Mercedes, the range is almost as good as when it was new—I can get 80 miles compared to the initial 90 miles, so it still feels as usable as when it was new. (That is not extremely usable, but that’s chiefly down to its lack of fast charging.) On the other hand, the newish DS 3 feels like it's going to be a long time before battery degradation has any meaningful impact on range. Fast charging might accelerate that, however, so it will be interesting to check in a few years' time.
So, take what you will from my anecdotal experience. It seems like at the end of the day, while charging cycles are a useful measure, they don’t give you the full picture.
Also worth mentioning is that a typical car warranty is only for 100,000 miles, which for a 200-mile range car equates to 500 charge cycles. So, the battery itself in an EV is likely to last four times longer than the warranty for the whole car. This is not surprising, as there has been gathering evidence of EVs making it as far as half a million miles with the original battery.
EDIT 28 Aug: Turns out the new California EV legislation specifically requires cars to have “battery health metrics“ for the benefit of second-hand buyers.