Level two charge rate varies

[Frankf]

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

 

[electriceddy]

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.

 

[Frankf]

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.

 

[Frankf]

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.

 

[OneEV]

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?

 

[Keith Smith]

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.

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.

 

[Frankf]

Regarding 50A charge: My mistake; the Chargepoint charger can go up to 50A (a whole 4% more, not worth worrying much about), but the EV6/Ioniq5 can take max of 11kW (about what you would expect 48A 240 circuit to produce).

I fully expect that the car should be able to charge at 11kW under most conditions. I examined the charge history from when I first got the charger January 2nd and almost all charging sessions started out at 11kW and within 20-30 minutes switched to ~7.2kW. The charging time is not insignificant. A 58.4kWh charge will take about 5.3 hours at 11kW vs 8.10 hours.
Yes, I charge at night and generally won't notice, but I expect it to be able to charge faster. I don't expect the charge rate to decrease that much through the charge. All of my graphs from chargepoint show a near sudden drop from 7.2 to 0. To the battery, AC and DC charging are the same (the ICCU converts the AC to DC). Battery life is a much bigger issue with an 18 minute charge at 350kW, about 32x the rate of the 11kW AC charger.

More importantly, is the damage that may be caused by the high temperatures (226F) at the charging connector. It suggests a poor connection, which over time will tend to get worse, corroding/oxidizing the connector pins, or connections between pins and wire. I am glad that the ICCU now reduces the AC charge rate when it gets too hot. But now they need to fix the problem causing it to get too hot. This ONLY effects AC charging. DC charging uses other pins and they are apparently built more robustly. I have not charged many times with a DC fast charger, but I had no problems with even a 350kW charger. It is nice to charge in 18 minutes, but I wouldn't want to do that very often. I will soon use the ODBC to measure DC charging temp.

If I get a chance (without voiding warranty) I will measure the voltage drop across the connector as well as the resistance. One person who looked into this had their problem go away (probably temporarily) after reassembling the connector pins.

 

[Keith Smith]

A 58.4kWh charge will take about 5.3 hours at 11kW vs 8.10 hours.
. . .
More importantly, is the damage that may be caused by the high temperatures (226F) at the charging connector. It suggests a poor connection, which over time will tend to get worse, corroding/oxidizing the connector pins, or connections between pins and wire.

One person who looked into this had their problem go away (probably temporarily) after reassembling the connector pins.

226F is definitely too hot somewhere. It should not be any hotter than the relay at the EVSE, My EVSE reports around 55C/125Fwhen it's 102F outside, I would think the connector should not really be warmer than maybe 150F-ish. So, ... VCMS inlet? Is that the J1772 plug on the body? This might be something as simple as collected trash/dust. I had a number of problems on my Kona with the J1772 socket. I got happy with some needle files, an air hose, and some WD-40. The problem went away.

If that referrs to the connection point behind the harness at the on-board charger, then I would do something there, though the OBC just might get too frickin hot. They may have used an under-gauge wire, should really be #4, or there could be a bad crimp or something. Good luck, I do agree if it says you can AC charge at 11K then you ought to be able to charge at 11K without moving to Siberia.

Stoopid idea maybe, does popping the hood open while charging change this? If it does it points to a ventilation issue.

 

[Keith Smith]

Apparently you are not alone. I ran across the TSB and people complaining about this. EV6 and IONIQ 5. According to those guys it just drops it to 5KW and leaves it there for the duration. Some people reported success by setting it to something in between 7.6 and 11.

I meant to note your math doesn't sound right, mythical 60KWH charge (~20% remaining):
60000/(240*48) (11520W)
5.2083
60000/(240*32)(7600W)
7.8125

Problem is neither calc figures in loss which is about 10% for round figures, thus draining your batteries close to 20%, applied energy to get 60KW in your 77KWH pack:
66000/(240*48)
5.7291
66000/(240*40) (9600W)
6.8750
66000/(240*32)
8.5937

So probably A little over 8-1/2 hours vs a little under 6. A little under 7 hours if you can sustain 40A. I've noticed my actual session times are always a little longer than the estimate, YMMV. I truly don't see a show stopper if I can fill up overnight. I actually use solar I work from home on Wednesdays excess solar output on a 32A charge is generally more than sufficient for a weeks worth of driving. If there is a solar output problem I've got from 8PM until 2PM the next day off-peak direct from the grid. I guess if your driveday is 6AM to 12PM, and you roll a couple hundred miles every day, the higher rate might be more desirable, but that seems very unusual.

I'm guessing this temperature issue is likely at the end of the harness not the plug, but I'd still get happy cleaning the socket and plug. I'd also check to see if you can drop the charge rate either at the EVSE or vehicle to something in-between as a work around. I have an EVSE that does the same thing to me, it starts charging at 32A gets hot and drops to 16A and just stays there. And I was pissed it did not perform to spec. If I set it to 24A it never misses a beat. Chinese junk. I keep it as a spare. I have an openEVSE now that works just fine. Thus I'd also be annoyed, likely enough to find where the heat sensor is that trips the alarm, and see what I could do to improve the connections at that point, an/or improve ventilation in that area. Gotta be the OBC getting warm doing the AC-DC thing ( I would think ), but 50A needs good clean connections to operate efficiently without heating up the connectors, and your probably not looking for much of a temperature drop to keep it from dropping down.