I heard something today that makes me very skeptical. A dealership claimed that charging an EV with 11 kW has higher energy efficiency than charging with 6 kW. (And they didn’t mean 3-phase vs. 1-phase!)
Even if it is somehow related to battery temperature and receptiveness, that would still be heat loss. With higher currents, resistance increases, too, no? Or is it proportional and always the same percentage?
In any case, I find it foolish to follow such advice because there are other factors involved, mainly a battery suffering more regarding longevity if charged faster, and that is a lot more expensive of a loss, eventually, also because an older battery is generally less efficient in several ways. (internal resistance, self-discharge)
Plus more load spike on the grid, external and house. But I don’t want to rant too much about the lack of reason in the world that seems to be a self-amplifying spiral of doom. Apparently house charger impatience is a thing. Three hours of charging twice a month - absolutely intolerable to some.
I know any L2 charging is far more efficient than 120V charging, after that the difference is said to be very small. Something like 72% efficient at 120V, but 82-85% at 240V.
I read if you want the absolute lowest charging losses run your charger at 80% of it’s max capacity. Like the cables are designed to carry 11kw/48A maximum with acceptable voltage drop, running it at 40A will cut that voltage drop. But in the end that may only be a cent or 2 of power lost/saved and not something to worry about.
This is all about 3-phase. I wasn’t aware the currents you mention are even possible with single phases.
Well, the 1-phase situation understandably looks even less feasible for the USA compared to Europe. There is reason for envy, haha: https://freespeechextremist.com/media/5c83dd3a-fb0d-4fee-9f45-57f8f73ecc6b/U.S. power grid when seeing European electric kettles [Dowlphin].jpg?name=U.S. power grid when seeing European electric kettles [Dowlphin].jpg