charging slow at Superchargers

[David99]

I've seen this at Corning and other places. In many cases, the handle was indeed quite hot. In at least two cases, it was barely warm and I still saw the reduced rate.

Yes I just came back from a 4500 miles road trip across the country. Over 30 Supercharging sessions. Sometimes the handle got hot, sometimes not, sometimes I saw a reduced rate, sometimes not. Most of the time, just unplugging and plugging back in increased the charge rate by 20-30 kW, sometimes it made no difference. At one Supercharger was a Tesla service guy who swapped out a cable. I charged at that stall (without anyone else there) and the charge rate was reduced. It's really inconclusive. I doubt it's a heat issue.
I also kept track of the battery temperature closely with TM-Spy. Interesting to see that at the end of the Supercharging session, the battery temperature was lower than before. In most cases the battery temperature dropped below ambient temperature at the end of the Supercharging session! The car is doing an amazing job cooling the batteries.
Once I arrived at a Supercharger with the battery at 51 Celsius (123 F)! Never seen it go that high from normal freeway driving. I got a reduced charge rate but the battery temp, again, dropped to 90 at the end of the Supercharge session.

 

[sorka]

Here's a typical chart of my charging sessions. This has occurred in Manteca, Atascadero, Gustine, Sebastopol, Fremont, Gilroy and Fresno. This does not include charge sessions from those SCs where I've plugged into bad stacks and never got a good charge rate to begin with. It's only at stacks that customer support reports to be in good working order without reduced service.

I point this out because we've got two different things going on this thread. 1) A number of charging sessions with reduced service stacks either due to utility peak limitations or stacks that need service because of some issue. 2) Cars that never EVER charge above a certain KW no matter what the plug into. Mine is in the latter category.

The following graph is typical of my charging sessions where the stack I'm plugged into is has no issues or limitations. In each of these cases I always start out high and then go down to the mid 60s or mid 40s within a few minutes.

In this case, I started at 15% and am down to the mid 40s KW in 5 minutes at 25%. I'd normally keep the full charge rate until 38% to 40% where it would finally start to taper off.

This last session had something happen that was new. While I was on the phone with Tesla, the entire car started shaking and there was a very loud scraping and clunking noise coming from the front for about 5 seconds. It sounded like something trying to turn but then stopped.

Battery temperature was 115F when I pulled in and stayed there while supercharging, so the cooling system couldn't be completely compromised but the horrible sound I heard made me wonder if it's working at a level that will allow the full charge rate. The CS rep told me the battery was a little warm and that it should have cooled off more after charging started.

We unplugged and gave up at 34% where we would have normally had no reduction in charging to that point. i.e the orange line above should have had no dip at all. I put on 48 miles in 14.6 minutes. Normally I would have put on 89 miles in 14.6 minutes.

Also, I didn't hear the often loud jet engine like sound that I've heard in the past on warm days. For instance, in July of 2015, we drove to Grants Pass in Oregon with 110F weather outside. It was freaky hot. Plugged in around 20% and almost as soon as it started charging, the cooling system become so loud I though there was something wrong but it just turns out that it was kicking in big time to keep the battery cool.

The charge taper did not deviate. We kept 110KW all the way through 40% where it finally started to taper.

 

[apacheguy]

Hmm. I'm thinking a cooling system failure is affecting your charge rate. With the battery over 40 C it will only take a couple minutes of 100+ kw charging to push the pack into 50 C territory. The BMS usually freaks out before 50 C though and that's why you normally hear the loud jet engine sound (compressor and fans).

 

[sorka]

Is anyone able to hold 110+KW past up to 37%? If so, what is your battery temperature?

 

[sorka]

Hmm. I'm thinking a cooling system failure is affecting your charge rate. With the battery over 40 C it will only take a couple minutes of 100+ kw charging to push the pack into 50 C territory. The BMS usually freaks out before 50 C though and that's why you normally hear the loud jet engine sound (compressor and fans).

So my battery temperature is always rising to about 115F (46C) after 30 minutes of driving regardless of the temperature. Is this typical? Anyone else seeing consistently lower temperatures after 30+ minutes of driving. Note, this was after driving in mildly heavy traffic allowing 60 MPH or so. My wh / mile from the time I left Santa Clara to the time I arrived at the SC in Manteca was 289 wh / mile, so I drove easy with no hard acceleration and very little regen.

 

[apacheguy]

No, that does not seem normal. Even driving in somewhat warm weather I find the pack temps are generally less than 40 C. Now, if you are supercharging, then you can easily get to 46 C even in mild weather.

 

[apacheguy]

My last dozen or so charges have been identical to these on superchargers that are NOT at reduced rates or reported to have issues. In the case when the SC is working fine, it starts at 114 to 116KW and then within a few minutes drops to 65KW and stays there flat until it the taper curve meets up with it where it would have been had it been charging normally and then decreases from there.

The very last time it went to 45 KW instead of 60KW (starting at 15%) and stayed there until I gave up and unplugged at 37%. I'll post a graph shortly.

I had an appointment last week to drop the car off at Fremont so they could diagnose the issue. The head diagnostic guy there said that if my car wasn't throwing codes then there isn't a problem and there's nothing they can do.

...

To their credit, the service manager was very nice and didn't doubt herself that I had a problem and she made me an expedited appointment in Dublin where they have normal super chargers for Monday morning.

Note, I've experience other slow charging sessions at other superchargers known to have issues, but the behavior is different. In those cases, I never get the full charge rate.

In the case where I believe it's my car, it's at SCs and stacks that are known to be good where I'm the only one on that stack and I always start at 114 to 116KW and then drop like a rock within a few minutes to 65KW.

How did the tech determine that there weren't any fault codes? Many of these are hidden and only visible remotely to Tesla. Did he pull the logs?

Wonder if shading the charging handle would help at all? If that's why the throttle is happening on the non-SPC limited Teslas, perhaps just wrapping the super charger handle in a white cloth to shade it from the sunlight would help... I'd dare say a wet white cloth might be better but high voltage and such could get the most cautious of us wearing a rubber glove when disconnecting

I've found that a wet towel works quite nicely. It's not any more or less dangerous than supercharging in rain or snow.

 

[sorka]

How did the tech determine that there weren't any fault codes? Many of these are hidden and only visible remotely to Tesla. Did he pull the logs?



I've found that a wet towel works quite nicely. It's not any more or less dangerous than supercharging in rain or snow.

Nope, he did not pull the logs. He said he doesn't have access to the logs at all which is surprising given that he's their head diagnostician. He said if there was any problem at all with the car that it would have told me to take it in for service and there'd be codes that they could see. I think what was really going on is that they're completely slammed and they didn't want to deal with it.

I have an appointment for Monday in Dublin(was going to be this morning but had to reschedule). At this point, the only way I'm going to get this resolved is if they open up a toolbox request which will get the engineers to do detailed log analysis of my charge sessions.

 

[David99]

So my battery temperature is always rising to about 115F (46C) after 30 minutes of driving regardless of the temperature. Is this typical? Anyone else seeing consistently lower temperatures after 30+ minutes of driving. Note, this was after driving in mildly heavy traffic allowing 60 MPH or so. My wh / mile from the time I left Santa Clara to the time I arrived at the SC in Manteca was 289 wh / mile, so I drove easy with no hard acceleration and very little regen.

That is unusually hot. Even in 90 degree temperature I hardly got over 100 battery temperature. Definitely not after just 30 min of driving.

 

[YellyYeti]

I saw this charging behavior also during my first long distance trip. This was at various Superchargers in Florida, Georgia, and South Carolina. Usually, I was the only car charging, external temperatures were around 90 degrees (and humid!). Charge rate would start at 106-116 kW, then drop to around 54 kW in a few minutes. I did not try switching stalls, as I assumed it was my battery getting too hot. The AC system would go full bore within a minute of being plugged in. The handle was quite hot. I did not call Tesla as I thought it was normal, but I am not so sure anymore after reading these posts.

Is there a way to see the battery temperature without doing any wiring? If I can get an instantaneous battery reading on my phone somehow, I could maybe isolate the problem. We have a trip to SC planned for the eclipse, so I could try experimenting while charging. I was planning to take a number of cold packs in ice in a cooler, to try to cool the handle down, to see if that makes a difference. Anything else I could try to identify the problem? It seems to be a pretty widespread problem.

 

[sorka]

Well I think I found a clue. At Manteca again and realized when I get out and walk to the front of the car that the cooling system is going full bore. It's just muted more than it has been in the past because both inlet louvers are completely closed. You can feel the air at the gaps being pulled in at high speed but they are shut.

I pulled in this morning with the battery at 110F (colder morning 73F out) and got a higher charge rate for about 5 minutes longer before it dropped to the mid sixes where it is now.

 

[apacheguy]

I saw this charging behavior also during my first long distance trip. This was at various Superchargers in Florida, Georgia, and South Carolina. Usually, I was the only car charging, external temperatures were around 90 degrees (and humid!). Charge rate would start at 106-116 kW, then drop to around 54 kW in a few minutes. I did not try switching stalls, as I assumed it was my battery getting too hot. The AC system would go full bore within a minute of being plugged in. The handle was quite hot. I did not call Tesla as I thought it was normal, but I am not so sure anymore after reading these posts.

Is there a way to see the battery temperature without doing any wiring? If I can get an instantaneous battery reading on my phone somehow, I could maybe isolate the problem. We have a trip to SC planned for the eclipse, so I could try experimenting while charging. I was planning to take a number of cold packs in ice in a cooler, to try to cool the handle down, to see if that makes a difference. Anything else I could try to identify the problem? It seems to be a pretty widespread problem.

Unfortunately Tesla does not expose pack temperature through the UI. You need a CAN bus tool to view. I can almost guarantee that it is not your pack temp that is limiting (unless like @sorka there is something very wrong with the cooling system).

Well I think I found a clue. At Manteca again and realized when I get out and walk to the front of the car that the cooling system is going full bore. It's just muted more than it has been in the past because both inlet louvers are completely closed. You can feel the air at the gaps being pulled in at high speed but they are shut.

I pulled in this morning with the battery at 110F (colder morning 73F out) and got a higher charge rate for about 5 minutes longer before it dropped to the mid sixes where it is now.

Have Dublin perform a thermal test and check the shutters.

 

[gavine]

Well I think I found a clue. At Manteca again and realized when I get out and walk to the front of the car that the cooling system is going full bore. It's just muted more than it has been in the past because both inlet louvers are completely closed. You can feel the air at the gaps being pulled in at high speed but they are shut.

I pulled in this morning with the battery at 110F (colder morning 73F out) and got a higher charge rate for about 5 minutes longer before it dropped to the mid sixes where it is now.

Those louvers should be open. I wonder if there's a software bug that's not allowing them to open during supercharging. Am I wrong...shouldn't they be open? They are only closed for aerodynamics when battery cooling isn't needed. When the AC is on or any battery cooling is needed (supercharging too), they open to allow air to flow over the heat exchangers. You might be on to something here.

 

[Zextraterrestrial]

Well I think I found a clue. At Manteca again and realized when I get out and walk to the front of the car that the cooling system is going full bore. It's just muted more than it has been in the past because both inlet louvers are completely closed. You can feel the air at the gaps being pulled in at high speed but they are shut.

I pulled in this morning with the battery at 110F (colder morning 73F out) and got a higher charge rate for about 5 minutes longer before it dropped to the mid sixes where it is now.

pretty sure the louvers should be open at the SC with the fans running at that charge rate and temp

 

[gavine]

pretty sure the louvers should be open at the SC with the fans running at that charge rate and temp

I hardly ever supercharge so I can't test but please report back if others (not just @sorka) have this same issue. It could be a fleet-wide bug of which Tesla isn't even aware. Next time you all supercharge, please check the louvers and report-back.

 

[apacheguy]

Doubtful this is a firmware bug. More likely that there is a hardware failure.

 

[gavine]

Doubtful this is a firmware bug. More likely that there is a hardware failure.

Agreed, but since so many people are having the same slow charging issue, I figured it was plausible that it could be a fleet-wide bug.

 

[apacheguy]

I've experienced similar reductions in charge rate as @David99 explains in the OP. I have verified that my louvers have always operated correctly.

 

[TexasEV]

When I had my 4-year service a few weeks ago one of the items was:
"During pre-appointment diagnosis, tech found radiator louver alert present"
"Correction- perform 2nd generation active louver retrofit"

I didn't even know my car had louvers.

 

[sorka]

I've experienced similar reductions in charge rate as @David99 explains in the OP. I have verified that my louvers have always operated correctly.

But at stalls/stacks that have been confirmed by tesla to be at 100%? The problem is the issue has become convoluted by the fact that there are a number of locations and stacks that really do have issues.