I have a couple Kia Niro PHEVs. They charge at a max nominal 220V 15A. One is in the shop due to some electrical problems and the dealer lent us a 2023 Kia EV6 Wind AWD. It is super nice.
I have two Wallbox Pulsar Plus EVSE stations that are hardwired in my garage and share a single 60A circuit/breaker. Both are independently capable of 48A charging, but I have a super awesome setup where they communicate via a Cat6 wire and I don’t have to worry about manually stepping down the amperage on one or the other when I plug two vehicles in at once - it’s automatic.
So I was looking at Kia’s spec sheet for the EV6 and it says the onboard charger is 10.9kW. But I plug it in to my super awesome charger (no other vehicle charging) and the EV6 dashboard reads 11.3kW. For its part, my Pulsar Plus station reports delivering 11.7kW.
Now, I figure my home voltage to be about 243V if I divide 11700W by 48A.
So, why is the Kia accepting a higher charge rate than 10.9kW? Is it because the kW rating Kia provides is based on a lower voltage than my house seems to have, and the car’s charger actually accepts a higher voltage?
Also, any guesses about the discrepancy between the station reported wattage (11.7kW) and the EV6 dash reported wattage (11.3kW)? I was thinking loss to heat, but 300W seems like a lot to me. Also, I tested the discrepancy at 6A increments from 6 to 48A and found that there was only a discrepancy starting around 30A and it was no noticeable discrepancy until about 30A (maybe 50-100W), increasing gradually at 36A, and 42A, until the discrepancy peaked at 48A (300W). The station, cables, and charging port were warm to the touch after an hour of charging but not over 90 degrees F for sure.
Sorry if I butchered any electrical or EV terminology. No flames please.
We have the Ioniq 5 and it’s the same hardware. First I wouldn’t worry about the numbers not being exact, +/- 0.4 kw won’t effect charging speed in a meaningful way.
I think it’s rated 11KW max charge rate but maybe that generic world rating, some other countries use slightly lower voltage, like 220-230. 48A at 230 would be 11.0kw, but if your at 243V the same 48A would give you 11.6kw.
You will have charging losses in the cable and at the connector plus when charging some power is being used to run the onboard devices like coolant pump and cooling fans if needed. So you may be putting 11.7kw into the car but only 11.3 into the battery.
One other thing another commenter mentioned that I think bears repeating here for posterity is that the EV6’s OBC is not limiting voltage input and the 10.9kW rating on it has probably more to do with the difference between the North American commercial, North American residential, Korean, and European nominal voltages which range from 208-240. At 48A, the 10.9kW number is a lot closer to the 220V standard in Korea than the 240V my house gets.
Also on voltage I think when the new charging standards are finalized it will include charging upto 277V. I believe that’s 2 lugs on a 480V 3 phase power and will allow large businesses and industrial locations to easily add EV charging on their existing 3 phase power supplies. Running 48A on 277V will give 13.2kw.
Thanks. Your comments are consistent with others, and I think the ~300W loss is probably mostly to heat, especially since it seems to increase at an exponential rate between 30 and 48A. Another person replying told me that heat is squared in proportion to current so that makes sense. Since you have pretty much the same hardware, do you know if the car (as reported on the dash) is measuring the charging rate before or after the OBC?