I have a 2024 EV6 and ChargePoint flex charger with 48amp capacity (#8 wire, 200a main). I charge when below 50% between midnight and 5am. Sometimes the charge rate stays at 48a/11kw throughout the charge. Other times it drops to 7.4kw after 40 minutes or so. Sometimes drops again. I have seen with dip for a few minutes and then climb back up. The voltage at the charger and service entrance does drop from 240 by a few volts, but not much unless I run AC, Electric dryer, electric oven, bath heaters and toaster oven. Even then it is around 234 volts. A big problem for me is that I have not yet found documentation that explains under what conditions the EV6, ChargePoint, or perhaps my utility throttles the charging rate. I don’t know if there is a problem nor what component is to blame. Sent from my iPhone using Inside EVs
#8 AWG conductors wrapped with 90 degrees insulation maximum capacity is 50A. This would be right on the upper threshold @ 48A continuous, and the breaker to handle that current would require a 2 pole 60 which is too large for the wire. I would start by replacing the feeder to the EVSE to #6 AWG with an ampacity of 65A. After that is done, check the temperature of the J1772 connector to eliminate any possibility of overheating issues using an IR heat detector or car scanning software/OBD2 adapter. I have doubts of any throttling from the utility end.
Upon further examination: The supply wire is 70' of #6/2 with #10 grounding with 60A breaker. The ambient temperature in Austin continues to climb, with nighttime low temps about 70. The Chargepoint continues to show initial charging of 11kW for 15-30min and then over 10-30 minutes ramps down to 7.4kW, although it sometimes wiggles a bit to 6.2Kw for several minutes. i have never seen the vent louvers open up in the car, nor heard any fan running while charging, but since I tend to charge from 10pm - 5AM I may have missed it. There is not much electrical load from other sources at that time of night. I can try a 65A breaker (definitely nothing larger) to see if it helps. I do want to get a scanner and ODB2 adapter, but having trouble deciding which one. I am getting increasingly suspicious of the ICCU, but without any error code or hard numbers I can't prove it.
Scanner for 48A (11.14kW) charge at 10pm with ambient temperature of 86F shows VCMS AC Inlet temp of: 186.8F after six minutes 201.2F after 10 minutes 215.6F after 15 minutes 226.4 after 21 minutes At this point the charge rate is throttled down to 7.2kW When I go to get ICCU patch, I will complain loudly about this. I would have returned the car if I had received it at this time of year instead of December. I paid for 50A charging ability. I can't wait until temps are in the 90s at night.
Frank I have the same Charpoint home flex and midnight to 6 am xcel energy plan. I have #8 and set for 40amps with 50 amp breaker. Perfectly fine for my ID 4 I drive uber early and at times hear the fans as I am loading up car in the morning. I am having an issue understanding why you think you should get 50 amps out of a 48amp max charger? especially continuous. You get the same issues with DCFC if heating reachs max temp then your charging speeds will slow down until inveror/batteries cool a bit . Am I missing somehting?
Your charge rate will drop the closer you get to 100% no matter what. Pretty steep time wise after 7.6KW, minutes, but it does drop. The slower you charge the battery the better it is for the battery life. Studies thus far seem to indicate the more fast charging the more degradation, not horrible but correlates. When connected to a DCFC my Niro will drop to 25KW at ~ 70%, and down to 12 @ 85% land down as low as 7.6 at 95%. I'm here in phoenix I charge my cars when it's 120F outside, I don't go below 7.6, I've never read the ODB2 on that one. Bottom line is the charge time difference is pretty small, there is 45min of overhead at the tail end no matter the rate, so figuring 1/2 fill of 35KWH 5h:15m vs 3h:30m while you are sleeping anyway, is kind of a push anyway. They really should address the cooling issue for the on-board.
