Slow DC charging ??

[hmadsen]

Soo, the other day i got a call from work to go urgently to a site 200 miles from my home.

My car was sitting in the driveway with 30 % SoT, the plan was to charge it the next day using solar power as the forecast said it would be sunny.

Had to leave urgently so drove away with 30 % SoT and ended up at a SuC with 1% SoT, the temperature was around 33F so very cold, the car only heated the battery for approximately 15 minutes right before i arrived so expected it to not be able to do very fast charging.

Plugged it in and was hit with 33Kw

Had to get something to eat so i thought i would just leave it, the app said it was heating the battery and charging would surely heat up the batteries as well, so i fully expected it to ramp up the power when the battery got warmer.

After 30 minutes it had only gone to 35KW so i decided to plan to go to the next SuC, where i would arrive with 12% SoT, the trip was only 40 miles. Drove off and was p*ssed to find the car was not immediately heating the battery like i thought it would.

After driving 25 miles it finally started heating, but 2 miles before the charger it turned off the heating even though the SoT was still at 10% so plenty of power to heat the batteries.

Plugged the car in, fully expecting it to be limited, but to my surprise it flew past 200 KW and did a normal charge and i was on my way. (So in reality the batteries had probably been well heated at the first charger, hence why it only did a bit of "maintenance heating").

Yesterday i had to do a 300 miles roundtrip so at some point i stopped to charge and even though it had been heating the batteries for 30 minutes and the temperature was more like 40F it again started charging at 33 KW.

I unplugged after 1 minute, reversed to the stall just behind and plugged in and again it just took off above 200 KW...

So...Now i think maybe there is a problem, either with those chargers or more likely my car.

Has anyone else experienced this and if so....Did you resolve it, and what was the problem ?

 

[ewoodrick]

I believe that what you were seeing is believed to be the cause of the great Chicago Winter debacle. Cold batteries don't like taking charge.

There is a lower number that the car will run the pre-conditioning at, it seems to have changed from 20% to 10% as you saw. 30 miles doesn't allow many options if something happens.

Okay, all that said, it is VERY possible that a single pedestal may be having issues. If you are plugged in and not getting the numbers that you expect, switch pedestals. It's not common, but it's far from uncommon. There have been a number of times that the rate has changed dramatically for me.

What rate Supercharger were you plugged into? Was it a V2 150kW and was there someone in the paired spot?

What did the Energy graph pages say? It gives you some decent information on reasons why you may not be charging at the proper rate.

 

[hmadsen]

I believe that what you were seeing is believed to be the cause of the great Chicago Winter debacle. Cold batteries don't like taking charge.

There is a lower number that the car will run the pre-conditioning at, it seems to have changed from 20% to 10% as you saw. 30 miles doesn't allow many options if something happens.

Okay, all that said, it is VERY possible that a single pedestal may be having issues. If you are plugged in and not getting the numbers that you expect, switch pedestals. It's not common, but it's far from uncommon. There have been a number of times that the rate has changed dramatically for me.

What rate Supercharger were you plugged into? Was it a V2 150kW and was there someone in the paired spot?

What did the Energy graph pages say? It gives you some decent information on reasons why you may not be charging at the proper rate.

Hi

Both sites has 250KW chargers.

I agree that the first time could be due to cold batteries, but would it not be fair to expect a car plugged in for 30 minutes, charging, while the app says "Heating battery for optimal charging rate" would heat up sufficiently for it to be possible to ramp up the wattage.

Also the first time it only heated the battery for 15 minutes and outside temperature was around 32F, so totally believeable that it would start off low.

Second one i dont think can be written off as a cold battery as temperature was actually around 48 (I was guestimating the 40 i wrote, we use Celsius here) and the car had heated the battery for a lot longer before i arrived.

I was more interested in, if the 33KW was due to some sort of "communication problem" or something, i find it odd that i have now twice in a few days seen exactly 33KW as the charge wattage at a V3 charger.

It would be really neat if there was some easy way of seeing the battery temperature and maybe even have the car tell you what the expected charge rate would be at that battery SoT and temperature. I mean, these limitations must be programmed into the car as kind of a lookup table.

 

[ewoodrick]

Hi

Both sites has 250KW chargers.

I agree that the first time could be due to cold batteries, but would it not be fair to expect a car plugged in for 30 minutes, charging, while the app says "Heating battery for optimal charging rate" would heat up sufficiently for it to be possible to ramp up the wattage.

Also the first time it only heated the battery for 15 minutes and outside temperature was around 32F, so totally believeable that it would start off low.

Second one i dont think can be written off as a cold battery as temperature was actually around 48 (I was guestimating the 40 i wrote, we use Celsius here) and the car had heated the battery for a lot longer before i arrived.

I was more interested in, if the 33KW was due to some sort of "communication problem" or something, i find it odd that i have now twice in a few days seen exactly 33KW as the charge wattage at a V3 charger.

It would be really neat if there was some easy way of seeing the battery temperature and maybe even have the car tell you what the expected charge rate would be at that battery SoT and temperature. I mean, these limitations must be programmed into the car as kind of a lookup table.

48F is still a cold battery It's only once the batteries get up into the 70's F (20s C) that they are considered warm.

Again, if you are getting les than you expect, the easiest thing to do is change pedestals.
Look at the details on the Energy Graph page,

Spring and Summer are coming, let's see what happens as the temps increase.

 

[hmadsen]

48F is still a cold battery It's only once the batteries get up into the 70's F (20s C) that they are considered warm.

Again, if you are getting les than you expect, the easiest thing to do is change pedestals.
Look at the details on the Energy Graph page,

Spring and Summer are coming, let's see what happens as the temps increase.

The battery was not 48, the ambient temperature was 48 and the car had heated the battery for a "long time".

Also, since i charged 1 minute at the charger that gave me 33KW, changed to another charger that instantly popped to well above 200KW i dont think it is a matter of a cold battery.

All i wanted to know is if this is a known error, or maybe i could do something different to avoid this.

I only see 2 options.

1. Faulty charger
2. Something faulty in my car....Maybe bad connector in the car, sometimes making a bad connection. If others had experienced the same and had their charge port fixed i would go do that.

What further complicates it for me is probably the fact that most people in here have a car with a NACS connector, but me being from Europe i have a CCS2 connector, so if this is something connector specific, not a lot of people would know i guess

In the future i will certainly change charger if i get below expected charge rate.

 

[ewoodrick]

Yes, the reason why I keep saying change pedestals is because there are sometimes problematic pedestals.

 

[hmadsen]

Yes, the reason why I keep saying change pedestals is because there are sometimes problematic pedestals.

Well then that's the answer, the pedestals can have problems.

I was just asking because maybe i did something wrong or maybe this was a knows problem with a fix.