[Roamer105]

I am surprised to see that SK battery's charging rate increase from 0 to 20 SoC.
What would explain this?

Mine has SK batteries. Recently I have charged at EA with nobody else there, so I got all of the power (so I thought). I started at 17% and went to 82% in 30 minutes. The interesting part is how it began: Battery at 70 degrees EA delivered 126KW, the BMS was asking for 176KW. Delivery increased over the next couple of minutes to 132KW as the battery warmed up. Stayed that way until about 35% then started to drop slowly but NEVER below 84KW with battery temperatures maintained at 100 degrees.

Based on the Car Scanner data, the BMS was asking for 176KW to start with batteries at 70 degrees, but EA did not deliver that and it took until the SOC reached 35% of SOC and battery temperature at 85 degrees until the BMS demand matched the EA delivery and the BMS started to control the delivery.

 

[Roamer105]

Thanks for the response. I appreciated it.
Two observations.
1. Increase from 126kW to 132kW was perhaps the battery heater going off?
2. Perhaps 132kW is the charger's maximum?

How did you determine that BMS was asking 176kW? I remember that there is current asked by BMS. Did you multiply the current by voltage? If you did, which voltage is you use?

Thanks in advance.

Battery voltage * max charge current. That formula works perfectly once the BMS gets in control of the charger so it is correct. I don't think the battery heater was on since the battery temp was around 70 degrees when it started. Later the cooling must have kicked in keeping it at 100 degrees, but did not appear to change much in regards to power to the ID.4 and the battery charge power recognized by the ID.4.

The screenshots show (i apologize for the current polarity misnomer) a close to initial point (around 24%), followed by about 33% with the last one around 74%. Unfortunately I did not take screen shots for the very beginning and the very end.

Note: These are actual BMS percentages not what is displayed on the dash. The display follows what appears a non-linear curve change from actual with the 100% at around 95% BMS and 0% at around 5% BMS where both of them match up around 55%.

 

[Roamer105]

I have to ask, are we sure the 2023 RWD SK and AWD are the same curve? I've had a number of EA sessions and never pulled anywhere close to that. Even looking in carscanner, I've never seen the car request near 180 kW. Looking through EA sessions, my all time max has been 135 kW at 20% on a EA 350 station. Yes I know other factors can come into play, but I've never been higher than that, and looking at what the car can request, it seems the max dynamic charging limit my car is 425 amps. That would mean that at a pack voltage of around 330, I can only pull 140 kW.

I have seen mine to peak at about 155KW at one time. But I have never seen the charger supply enough to satisfy the BMS request. I also never charged anywhere other than EA. The 2023 SK battery does allow charging up to 175KW or thereabouts.

 

[Roamer105]

Was it a 150kw or 350kw EA station? Some stations have a cap on amps which maybe you hit. 400A x 312V = 125kw and I would not be surprised if EA mis-labeled a little.

I don't trust EA labeling but it was a 350KW station.

 

[Roamer105]

I can see that your gauge in the middle of the screen is doing the [Battery voltage * max charge current] math (although I don't understand the polarity misnomer bit), but how did you set that up? I have the full version of the app but I can only see the "select multiple sensors" link for a fraction of a second when customizing a page and then I can only select one sensor per item. I haven't found a how-to on this forum or on the developer's website, so presumably it's obvious and I'm just being a dufus.

—Eric

It is a PID you can select (HV Power). The polarity is seems reversed but it is just a question of point of view. I like green for charge current and red for discharge.

 

[Roamer105]

Thanks. I fixed it in my dashboard. I'm still not clear on where you came up with 176kW, since I don't see it reflected in your screen shots, but maybe you were doing the math outside of the app. I'll see if I can figure it out next time I fast-charge. I think it would be useful to know, since these cars, unlike some others, don't tell us when the power is limited by the dispenser.

--Eric

Yes, if you multiply the charge current limit with the battery voltage you get the KW charge amount the car is asking for. These values change dramatically with battery temperature and SOC.

 

[Roamer105]

I have seen an amazing charge recently at my local EA station. As you can see the outside temperature wa 97degrees. I was the only car charging at the time so I got access to all power and the car was asking for 175KW while sitting at 22%.
2023 PRO S AWD with SK battery