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.

  • ultimateusername123OPBEnglish
    1·
    1 year ago

    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.