Charging loss on DC fast?

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FloridaSun

FloridaSun

Well-Known Member
I'm charging right now on a free 50kw charger.. At this point, I have added 32% of charge and the charger shows 44.8kwh delivered.. As the Kona has a 64kwh battery, this would indicate a very high loss.. Can this be accurate? I will charge to 85% and see what total kwh will be delivered for 69% of charge.. If it charges at that efficiency, I should receive more energy than the battery size..

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Were you running any climate controls while charging? On some cars HVAC draws power directly from the charger when plugged in. Although your numbers are much higher than I would expect.
 
I will charge at another charger to see if it was an issue with the charger.. The car showed 42kwh to 49kwh charging speed as did the charger. based on the charging time, I indeed received 88kwh. It appears to be a loss at the car. If this happens again at another charger, I may have to bring the car to Hyundai to have it checked.. Something does not seem right.. There seems to be parasitic loss when charging DC.. On my home EVSE, the numbers seem right with about 10% loss.. The DC loss seems to be about 50%.. That'a insane.. Air temperature was about 93F, 34C... Maybe battery cooler came on but 50% loss from that?
 
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just to add, I ended the session at 79%. So, charging the car from 16 to 79 percent took 88kwh. That'a a 50% loss somewhere on the car. Over 2 hours, mostly at 42kwh to 49kwh between 16 and 75% SoC and about 34kwh after 75% SoC
 
Any indication of TMS operation?
If there were an issue with the pack such as high internal resistance, I would think the battery care display would show the first indication of protection.
Do you run Torque Pro- curious of the temp and voltage of each cell group.
The following article helps distinguish (start at section 6)
https://www.sciencedirect.com/science/article/pii/S2590116819300116
I would have thought communication error, but seeing as the car dash display reports the same speed and the time duration calcs, something else might be going on.
Keep us informed.
 
electriceddy said:
Any indication of TMS operation?
If there were an issue with the pack such as high internal resistance, I would think the battery care display would show the first indication of protection.
Do you run Torque Pro- curious of the temp and voltage of each cell group.
The following article helps distinguish (start at section 6)
https://www.sciencedirect.com/science/article/pii/S2590116819300116
I would have thought communication error, but seeing as the car dash display reports the same speed and the time duration calcs, something else might be going on.
Keep us informed.
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I should have run Torque Pro during the charging.. I will certainly run it next time on a DC fast charger.. I'm sure that the car received 88kw as it matches what both, the dash and the charger indicated. I just don't know where the excess charge went.. I'm sure that TMS came on.. It always does come on when I charge during hot weather on DC fast. However, I can't see how TMS can pull 30% or so from the charge current.. Weather has been unusually summer like lately but a cold front is coming through, forecasted to cool us down from 34C to 30C but nights will drop down below 15C.. That will be nice..

Another thing that I noticed was that the charger actually indicated SoC BMS, not SoC Display..
 
Charged again on DC Fast on a different charger and this time I had no unusual loss. TMS came on during the last 10 mins of the session, so it ended up taking 36 instead of the predicted 34 minutes. Outside temp was about 10 degrees lower than when I had the original issue.. 83 F/28C vs 93F/34C last time. Charged from 47 to 80%.

Monitored the charging process with torque pro and the numbers on the dash matched both the numbers shown on the charger as also on Torque Pro. No parasitic loss this time.
Screenshot_20200404-210604_Greenlots.webp
Screenshot_20200404-162815_Torque.webp
 
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BlueKonaEV said:
Charged again on DC Fast on a different charger and this time I had no unusual loss. TMS came on during the last 10 mins of the session, so it ended up taking 36 instead of the predicted 34 minutes. Outside temp was about 10 degrees lower than when I had the original issue.. 83 F/28C vs 93F/34C last time. Charged from 47 to 80%.

Monitored the charging process with torque pro and the numbers on the dash matched both the numbers shown on the charger as also on Torque Pro. No parasitic loss this time.
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That's good news. must have been some kind of communication error on the first charger. I wonder if any others have reported the same issue on Plugshare.
 
electriceddy said:
That's good news. must have been some kind of communication error on the first charger. I wonder if any others have reported the same issue on Plugshare.
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Didn't see any similar issue with that charger.. Weird thing is that according to the dash readout, the 88 kwh delivered match the average speed and charging time.. It's so weird.. I don't really think that it's an issue with the chargers. Of course, if the dash readout would have been for example 44 kwh speed and the dash read 22 kwh, I would say that it was an issue with the charger but everything displayed on the charger mirrored what the dash readout showed. I did watch the dash readout for the first 44 kwh delivered and I never saw a difference between the charger kwh readout and the dash kwh readout..
 
BlueKonaEV said:
Didn't see any similar issue with that charger.. Weird thing is that according to the dash readout, the 88 kwh delivered match the average speed and charging time.. It's so weird.. I don't really think that it's an issue with the chargers. Of course, if the dash readout would have been for example 44 kwh speed and the dash read 22 kwh, I would say that it was an issue with the charger but everything displayed on the charger mirrored what the dash readout showed. I did watch the dash readout for the first 44 kwh delivered and I never saw a difference between the charger kwh readout and the dash kwh readout..
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I guess the first thought that comes to my mind is that if it is really true that the 1st charger really delivered 88kWh, then whatever didn't make it to the battery would have needed to go somewhere and that is most likely that it was just converted to heat, and a lot of it.

I keep thinking that the 1st charger is defective. It might have told you that and the car that it was delivering say 44kW at a given moment but it might have only delivered half that. We already know that the car and the charger communicate so as to agree on a charge rate, and this changes from time to time - I am wondering if the car only displays the number that the car and charger agreed upon, and that if the charger was unable to deliver that you wouldn't see an indication of this.

A shame you didn't have Torque Pro running when charging on that 1st charger.
 
electriceddy said:
Curious as to why indicated "works flawless" on Plugshare check ins
https://www.plugshare.com/location/201638
when report differently here
https://insideevsforum.com/community/index.php?threads/charging-loss-on-dc-fast.8597/#post-96610
am I missing something?
BTW no shortage of charging locations in your area...lucky:rolleyes:
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Well, I didn't think (and still don't think) that it was an issue with the charger. What I also meant is that there was no issue initiating the charger and charging to the desired level. As I said before, the car indicated that I got exactly the kwh speed on the dash that the charger indicated, so I don't think that it was an issue with the charger itself. I was in the car for the first 45 minutes or so of charging and I could not see any discrepancy between the read out on the charger and my car. It's like having a liter/minute (or gallon/minute) gauge on a gas car and the gas pump would show the same amount of gas dispensed as the car indicates that it received.. In that case, I would also doubt that the issue was with the pump.
Maybe I'll have to go back to the same charger next time I'm in that area.. I don't really live in that area.. I live 60 miles away but my parents live less than 10 minutes from both of those chargers and on the weekend, I go to my parents condo in Clearwater and I take advantage of the free DC fast charger there. Pinellas county (Clearwater/St. Petersburg) is one of the best locations IN THE COUNTRY and maybe in the world when it comes to FREE DC Fast chargers. There are 4 free 50kw DC Fast locations and a couple Harley Dealerships with free 24KW DC Fast chargers as also 2 FREE Greenlots chargers for College Students and Staff in Downtown St. Pete (Other people often charge there but you are supposed to have college parking pass to enter that garage). The closest FREE DC Fast charger is about 28 miles from my house and it's at a Harley Dealership. We have a local Harley Dealership in my town but they started charging $3 per hour plus 10 cents per kwh for the charge, so it's no longer free. We have some free level 2 but no free level 3.. Just one EVGo 40kw charger and the one at Harley.
 
ericy said:
I guess the first thought that comes to my mind is that if it is really true that the 1st charger really delivered 88kWh, then whatever didn't make it to the battery would have needed to go somewhere and that is most likely that it was just converted to heat, and a lot of it.

I keep thinking that the 1st charger is defective. It might have told you that and the car that it was delivering say 44kW at a given moment but it might have only delivered half that. We already know that the car and the charger communicate so as to agree on a charge rate, and this changes from time to time - I am wondering if the car only displays the number that the car and charger agreed upon, and that if the charger was unable to deliver that you wouldn't see an indication of this.

A shame you didn't have Torque Pro running when charging on that 1st charger.
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If the first charger was defective, why would the Kona indicate that it received exactly the kwh that the charger showed it was sending.. The whole thing is mind boggling. Why would the Kona indicate that it received 44kwh speed if the real speed was 22kwh? Does it just mimic back what the charger is telling it what it sent or does the car measure the charge itself?
 
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