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.
I think you confuse the specs of the PHEV version with the full electric one
Thanks for taking the time to reply. I’m sorry I wasn’t clear enough in my question. Other replies have seemed to understand what I was getting at. The only reason I mentioned the PHEV Niros was because I was trying to provide a backstory for how I ended up with an EV6 in my garage on loan, and also so nobody would wonder why I had two Wallbox stations in power sharing mode. I guess I could have simplified the whole thing by not mentioning the PHEVs and the dual EVSE stations, especially since none of the really good replies are pointing to the power sharing setup as a potential cause.
Both the EVSE and the cars monitoring equipment will have accuracy range, plus and minus. The EVSE is telling you what’s passing through it. Is the car telling you what’s coming in through the port or what’s going into the battery. I would thing the later. That discrepancy is what the car is using for internal electronics doing there thing.
300 Watts are pretty much the commonly accepted rule of thumb for the onboard charger’s consumption. Also, imprecisions are pretty common in all sorts of equipment. My former wall charger constantly under-measured voltage by 10% and now that it was replaced (for different reasons) I’m seeing close to the full 11 kW for the first time.
Normally I’m freakishly good at geolocating askers from things they say, but somehow it short circuited and I’m placing you in the UK. I don’t even think they sell the Wind in the UK.
No matter, UK, Canada and US all have the same target system voltage of 240V, and 243V is perfectly within spec, especially at non-peak hours.
EVs tightly regulate amps. Volts are “catch as catch can”. So your car may well be specced @ 230V for the EU market or even 220V for Kia’s home market of Korea. Charge rate will vary in proportion to voltage, since amps are pegged.
Now about that 48A charge rate. As Technology Connections famously says, “Don’t just get the Fastest Charge Possible… it’s expensive, and may come with more headaches than you bargained for”. On r /evcharging and here, we tend to see this as an endless parade of melted stuff. Running at max for hours will find any flaw in the work and make it crispy. Since you don’t have a pants-on-fire need for 48A, you might want to clock that back to 32A. That’ll reduce thermal load on wires (and importantly, splices and connectors) by more than 50%. Heat being the square of current. Dropping further to 24A will reduce thermal loads by 75% to 1/4. I realize it isn’t your Kia whose port you’d be burning up at 48A, but they’re infamous for melting the charge port.
Thanks for that. I’m not an EE, so I was unaware that heat rises exponentially with current.
I definitely had things done right with my home install - dedicated circuit, licensed electrician, etc. I was looking forward to testing out my setup at 48A, which I’ve now done for a few days.
I haven’t had any sessions longer than about two hours at 48A, but both my system and the EV6 performed flawlessly. I’m going to conclude from your answer that I’m simply losing ~300W at 48A to heat. It’s hard to tell if I’m losing it before it gets to the the OBC. I wish I knew where EV6 measured it, before or after the OBC.
US Here
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.
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?
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.