2 charging issues

[navguy12]

I was recently at the mall where 10 Tesla Superchargers were in use. The Tesla Charger repair man was there and I struck up a conversation with him. He told me that if you are using a Double Charger where two cars can charge at the same time, one on each side, this will slow your charging down. He also pointed to a Large Transformer the size of 2 Refrigerators over in the bushes about 200 feet from the charging stations. He said it was supplying electricity to all 10 of the Superchargers and that every time another car hooks up to any of the Superchargers all the Chargers are affected and will slow down. He may be full of it, but this is what he told me. You Electrical Engineers on here can say if he is right or wrong.

Slightly in error.

Version 2 (150 kW) units are electrically “paired” (1a, 1b, 2a, 2b, etc). Tesla owners charging technique is to not attempt to attach to the same paired unit as where someone else is already charging because you (not the person already charging) will be capped at 60 kW (+/-) until they are either done or tapering to 60 kW or below.

V 3.0 (250 kW) units do not have this limitation.

Example: I pulled into a V 2.0 SC station in central Toronto last week, all the paired units had at least one car plugged in, so no matter where I was going to plug into, my max rate would be capped at 60 kW until the unit I was paired with was disconnected. When the chap next to me was done, he disconnected and I throttled up to 140ish kW.

As an aside, as is typical for my experience at long (20 min) SC stops, by the time I went to the restroom and back and then ate a bagged lunch, the car was done.

 

[Frank Pierson`]

Absolutely. The transformers are not only to drop a voltage to something usable, but to also limit the current available. Depending on if they are a autotransformer. Large motors before electronic starters used them for the same reason to prevent overloading the supply grid. It will only produce the rated KVA before the voltage drops off.

 

[rpark]

Actually, they lowered it from 77 to 75 kW for the 2022 model, but I have only seen close to that rate in optimum conditions when the ambient temp is well above 70 degrees and only with low SOC. If you are getting a better rate at a 50kW charger, I would stick with those machines until the conditions are more favorable.
"At 75.0 kilowatts, the Kona also has an above-average charging rate, with the Kia Niro EV being the slightly better of the two with a max charging rate of 77.0 kW."

Thank you for the information. From what I can recall both times the battery was at 15%, battery temp was 28C, outside temp around 10C. First time was at Petro-Canada 150kwh and on the way back it was at co-op 100kwh. Both times the charge rate reached 40kwh no higher. I called dealer and booked in there 3 weeks from now. Will post the results.

 

[Humane]

I have a '20 Kona. When it was new it would charge at up to 74kw. Now it charges at 40-42 kw, regardless of what the output of the charger is. I spoke to dealer, they didn't give a definitive answer, just that it varies....

 

[rpark]

Thank you for the information. From what I can recall both times the battery was at 15%, battery temp was 28C, outside temp around 10C. First time was at Petro-Canada 150kwh and on the way back it was at co-op 100kwh. Both times the charge rate reached 40kwh no higher. I called dealer and booked in there 3 weeks from now. Will post the results.

Just noticed I left this reply hanging. The Kona was traded in before the dealer visit so it’s unknown what the issue is.

 

[Joev]

I have a '20 Kona. When it was new it would charge at up to 74kw. Now it charges at 40-42 kw, regardless of what the output of the charger is. I spoke to dealer, they didn't give a definitive answer, just that it varies....

There are many reasons you might not see the higher rate of charge. With the Kona, any charge station over 100 kilowatts will not give you you any faster or higher charge rate. If possible try to pick a level 3 charge station that is close to your vehicle's maximum that it can receive. Like you mentioned seems to be about 74 to 80 kilowatt at the best rate.
So if you pull into a plaza with multiple stations try to save the higher kilowatt ones for vehicles that can accept a higher charge rate. Unless there are none others open or are not available because they are out of service then use whatever one you can grab.

The main reason this time of year is because of the cold temperatures and or a low state of charge. The battery cannot take a high rate of charge with colder ambient temperatures and if the battery is not warmed up. The battery management software is protecting the battery and it has a direct influence from the temperature. I have noticed I do not get maximum charge rate until its around 70° f outside air temperature.
Don't panic, it is totally normal. I'm sure you have noticed your range has decreased also, welcome to the EV world. By the way if you had an ICE vehicle your MPG would also decrease in cold weather.

I will try to find my charge rate drop off chart that is a guideline for different charge rates throughout the charge session. I am not sure if it is exactly current with the latest software updates to the battery management system. But it would show you just how it various throughout the session.

 

[Joev]

I found this chart after my first road trip in frigid weather with my 2019 Kona EV.
I was ready to pack it in then realized it's normal for batteries in cold temperatures.

I have other charts that show different charge rates at different state of charge but they don't show battery temperature or ambient temperature so I did not include them.

 

[electriceddy]

I found this chart after my first road trip in frigid weather with my 2019 Kona EV.
I was ready to pack it in then realized it's normal for batteries in cold temperatures.

I have other charts that show different charge rates at different state of charge but they don't show battery temperature or ambient temperature so I did not include them.

View attachment 19418

Corresponds closely with this (ambient temperature included)
Good to know on fast chargers:
Battery temp < 1 degC : max power 18 kW
1 degC > Battery temp > 5 degC: max power 25 kW
5 degC > Battery temp > 15 degC : max power 40 kW
15 degC > Battery temp > 25 degC: max power 50 kW (50kW chargers) or 56 kW (>100kW chargers)
Battery temp > 25 degC: max power > 70 kW (>100kW chargers)
Thanks to @herode10

 

[BaylorBob]

Slightly in error.

Version 2 (150 kW) units are electrically “paired” (1a, 1b, 2a, 2b, etc). Tesla owners charging technique is to not attempt to attach to the same paired unit as where someone else is already charging because you (not the person already charging) will be capped at 60 kW (+/-) until they are either done or tapering to 60 kW or below.

V 3.0 (250 kW) units do not have this limitation.

Example: I pulled into a V 2.0 SC station in central Toronto last week, all the paired units had at least one car plugged in, so no matter where I was going to plug into, my max rate would be capped at 60 kW until the unit I was paired with was disconnected. When the chap next to me was done, he disconnected and I throttled up to 140ish kW.

As an aside, as is typical for my experience at long (20 min) SC stops, by the time I went to the restroom and back and then ate a bagged lunch, the car was done.

Slightly in error.

Version 2 (150 kW) units are electrically “paired” (1a, 1b, 2a, 2b, etc). Tesla owners charging technique is to not attempt to attach to the same paired unit as where someone else is already charging because you (not the person already charging) will be capped at 60 kW (+/-) until they are either done or tapering to 60 kW or below.

V 3.0 (250 kW) units do not have this limitation.

Example: I pulled into a V 2.0 SC station in central Toronto last week, all the paired units had at least one car plugged in, so no matter where I was going to plug into, my max rate would be capped at 60 kW until the unit I was paired with was disconnected. When the chap next to me was done, he disconnected and I throttled up to 140ish kW.

As an aside, as is typical for my experience at long (20 min) SC stops, by the time I went to the restroom and back and then ate a bagged lunch, the car was done.

Since I don't have a Tesla and will never be getting one and also because I have my own Level 2 Charger at Home, none of this will affect me. I found your answer about the 1st Car to hook up getting the most Electricity to be a Good Trivia Question!

 

[hobbit]

I saw my '21 touch 80 kW very briefly on a new EA unit on a recent trip up from FL. It was *after* the big cold
snap, the day was maybe 50F and it was later in the day so the pack was up to 90F or so from running and
previous charges. That's a lot of thermal mass, it takes a while to stabilize at its "comfy" temp..

_H*