Weird Supercharger Incident (Reduced Charge)

[scaesare]

So this just happened to me yesterday at the Woodbridge, VA supercharger and I immediately recalled this thread. I just reread all the posts and many of the aspects of my charging session were similar:

- Hot day (low 90's), as well as somewhat humid.
- Low initial SOC (<10%)
- Had been driving at highway speeds prior to plugging in
- Only car at the site

Once we started charging I immediately walked away (wife needed the facilities lol), and only when I looked at the phone a few minutes later did I see I was pulling 72A. I did the calcs quickly and realized I was only only about 25.6KW. At that time I was seated in a restaurant a bit away, and didn't go check anything, as I was only a short distance from home and knew I'd be ok. But I monitored, and the current never rose above 74A.

When I went back to the car:

- I was still the only one there
- The thermal management on the car was running strong (although I had also used the app to pre-cool the car with the HVAC)
- The blower on the supercharger cabinet was running (interestingly it appears that most of them were running, despite only one car plugged in)

I did notice that the screens on the supercharger cabinets may have had a little debris in them, but it didn't appear too major. This is also a relatively "young" site.

I surmised this was a heat related issue with the pack in my car. Although I've charged in similar hot weather before, and didn't have this issue. This location is only about 40 miles fro my house (a bit less as the crow flies), and also haven't had the issue here.

Odd. I wish I would have called Tesla.

 

[X Fan]

The thing is that these incidents only occur at people's local supercharger

From personal experience, don't agree.

FL Resident and have seen some stalls in Ga and Va sites that have been much slower than others. Switched and result was much better.

Btw: agree re: Woodbridge. Used while traveling through 2x over last 45 days and very slow both times. Will try to skip going forward.

 

[Electric700]

So this just happened to me yesterday at the Woodbridge, VA supercharger and I immediately recalled this thread. I just reread all the posts and many of the aspects of my charging session were similar:

- Hot day (low 90's), as well as somewhat humid.
- Low initial SOC (<10%)
- Had been driving at highway speeds prior to plugging in
- Only car at the site

Once we started charging I immediately walked away (wife needed the facilities lol), and only when I looked at the phone a few minutes later did I see I was pulling 72A. I did the calcs quickly and realized I was only only about 25.6KW. At that time I was seated in a restaurant a bit away, and didn't go check anything, as I was only a short distance from home and knew I'd be ok. But I monitored, and the current never rose above 74A.

When I went back to the car:

- I was still the only one there
- The thermal management on the car was running strong (although I had also used the app to pre-cool the car with the HVAC)
- The blower on the supercharger cabinet was running (interestingly it appears that most of them were running, despite only one car plugged in)

I did notice that the screens on the supercharger cabinets may have had a little debris in them, but it didn't appear too major. This is also a relatively "young" site.

I surmised this was a heat related issue with the pack in my car. Although I've charged in similar hot weather before, and didn't have this issue. This location is only about 40 miles fro my house (a bit less as the crow flies), and also haven't had the issue here.

Odd. I wish I would have called Tesla.

You can still contact Tesla at [email protected]. If you decide to do so, you should include the Supercharger location and a request for them to review your logs (just in case). If it is Supercharger maintenance-related (checking the air filters/fans and other back-end equipment), I think they will send someone out to that location.

 

[SomeJoe7777]

Here is the graph of my supercharger session that shows the reduction in power.

It held a normal 115 kW for about 10 minutes, then dropped to only about 20 kW, and remained there for the rest of the charging session. My cooling fans were not running, despite 100F+ temperatures.

This was at the Lindale, TX supercharger (brand new) on Friday, 7/22.

This has to be some type of thermal issue, either with the car or the supercharger cabinets. And I want to know why my cooling fans weren't running.

 

[NOLA_Mike]

One of the places it happened to me was Lindale, TX. I moved to another charger and it resumed at high power.

 

[SomeJoe7777]

One of the places it happened to me was Lindale, TX. I moved to another charger and it resumed at high power.

The plot thickens.

I had heard that the delay in opening the Lindale supercharger was because there were electrical issues. I wonder if there are some voltage problems that are causing the supercharger to limit its output? Similar to how the car will limit the battery charging rate using the onboard chargers if the input voltage drops too much.

I will be going back to the Lindale SC on 8/20. If this happens again, I will definitely call Tesla and inform them.

 

[rypalmer]

Here is the graph of my supercharger session that shows the reduction in power.

It held a normal 115 kW for about 10 minutes, then dropped to only about 20 kW, and remained there for the rest of the charging session. My cooling fans were not running, despite 100F+ temperatures.

This was at the Lindale, TX supercharger (brand new) on Friday, 7/22.

This has to be some type of thermal issue, either with the car or the supercharger cabinets. And I want to know why my cooling fans weren't running.

I experienced the exact same issue at two Superchargers in Ontario this past weekend. Neither were that close to "home" and neither had other cars charging.

 

[Ampere_90D]

I've just had the issue occur in the last 1 hour from this posting, and also on the last three weekends. What I'm seeing is identical to all of your observations, except it only seems to happen when the car is drawing more than 250 amps. Range mode is off, battery started at 15%, and the location is at the supercharger on Houston Northwest FWY. The current dunked after 10 minutes of 292-294amp charging. I then switched to the neighboring stall which charged for another 5 minutes at 282-292 (decreasing slowly because my battery had hit 50%) before the current took another dive. The current cap in this state is 74 amps. No more, and only less if you run the AC. This tells me one important thing, which is there is absolutely a firmware imposed current cap somewhere because the car should draw extra current for the AC from the supercharger and not the charge current alotted to charge the battery. My current operating theory (based on some deeply drooping current numbers during the charge), is that the supercharger senses a power quality issue and so it drops the current briefly. The code in the car that was modified to handle higher amperages for supercharging in newer models sees this dip and some routine in the code was programmed to flag this as a latchable supply error which clamps the current to protect the car from fluctuating power supplies.
I have a query and car data out to tesla about this (I was on the phone with their tech support while I was charging and he made a timestamp of the exact moment the current dropped), and I hope to hear back from them soon.

 

[Ampere_90D]

Update: The guy with old nose cone style next to me (different bay pair) was at 89 miles range, and was also clamped to 74a after a short period. If this is a car issue, then it is increasingly likely to be a widespread firmware bug

I've just had the issue occur in the last 1 hour from this posting, and also on the last three weekends. What I'm seeing is identical to all of your observations, except it only seems to happen when the car is drawing more than 250 amps. Range mode is off, battery started at 15%, and the location is at the supercharger on Houston Northwest FWY. The current dunked after 10 minutes of 292-294amp charging. I then switched to the neighboring stall which charged for another 5 minutes at 282-292 (decreasing slowly because my battery had hit 50%) before the current took another dive. The current cap in this state is 74 amps. No more, and only less if you run the AC. This tells me one important thing, which is there is absolutely a firmware imposed current cap somewhere because the car should draw extra current for the AC from the supercharger and not the charge current alotted to charge the battery. My current operating theory (based on some deeply drooping current numbers during the charge), is that the supercharger senses a power quality issue and so it drops the current briefly. The code in the car that was modified to handle higher amperages for supercharging in newer models sees this dip and some routine in the code was programmed to flag this as a latchable supply error which clamps the current to protect the car from fluctuating power supplies.
I have a query and car data out to tesla about this (I was on the phone with their tech support while I was charging and he made a timestamp of the exact moment the current dropped), and I hope to hear back from them soon.

 

[rypalmer]

I've been getting consistently bumped down to 55kW and even as low as 22kW all while having SoC under 50%, after an initial successful start to the charge around 96kW. One new theory I've been playing around with: that the car is rate limiting me one it knows I've charged enough to reach my programmed destination. It's early days for this hypothesis, though.

 

[Ampere_90D]

UPDATE: Just got off a call with Tesla. The issue is 100% known and an issue with some supercharging stations which are using newer technology. I'm being told that the issue is being investigated, and I have asked for an email reply when the fix has been identified and executed. Tesla claims that for now, the only workaround is hopping between bays as soon as the issue presents itself. In my own personal experience, one should only have to do this two or three times before reaching about 50% battery on a 90D (about 250a charge rate), which is when the issue seems to stop re-occurring after the last switch to a new bay.

 

[cpa]

I had noticed this also a couple of times this year while Supercharging. I generally am not on a firm timetable, so an additional 10-15 minutes doesn't matter to me.

What confuzzles me is that how can this happen so suddenly? Frankly, I have wondered about software problems
that crop up unexpectedly and unannounced when previously the programs worked seamlessly. Despite decades of invention and creation is the software industry still trying to figure things out? (This is not sarcasm, but if something works well, why screw it up?)

 

[scaesare]

Given the chargers used in Superchargers are the same ones in the cars, I'd expect that superchargers also receive firmware updates. I suspect that the issue could be an update on that side...

 

[rypalmer]

Same issue last night charging at Toronto SC. SoC <10%, few other cars charging but none sharing my charger stack. Charging ramped to ~96kW as usual, but abruptly cut to 20kW after about 8 minutes of charging. Had to switch stalls twice, and got the same issue all 3 times.

Same issue as in Port Hope this past weekend.

 

[Kalud]

UPDATE: Just got off a call with Tesla. The issue is 100% known and an issue with some supercharging stations which are using newer technology. I'm being told that the issue is being investigated, and I have asked for an email reply when the fix has been identified and executed. Tesla claims that for now, the only workaround is hopping between bays as soon as the issue presents itself. In my own personal experience, one should only have to do this two or three times before reaching about 50% battery on a 90D (about 250a charge rate), which is when the issue seems to stop re-occurring after the last switch to a new bay.

I'm back from my Montreal - Miami - Montreal annual roadtrip and can confirm this and its more-or-less widespread. Talked to Tesla a couple times during my trip. I've seen this occur to me on many supercharging session I had. One way Montreal to Miami is 15 charging stops. I've moved stalls multiple times and it always solved the issue until it did it again. Tesla on the phone always just said "Yeah we know, these stalls are on reduced power mode, a technician is already scheduled". I've seen things like that in the past but this year it was on many stops and actually made us wait more than usually. On a 29h trip it makes a difference...

 

[David29]

UPDATE: Just got off a call with Tesla. The issue is 100% known and an issue with some supercharging stations which are using newer technology. I'm being told that the issue is being investigated, and I have asked for an email reply when the fix has been identified and executed. Tesla claims that for now, the only workaround is hopping between bays as soon as the issue presents itself. In my own personal experience, one should only have to do this two or three times before reaching about 50% battery on a 90D (about 250a charge rate), which is when the issue seems to stop re-occurring after the last switch to a new bay.

Glad to hear that Tesla acknowledges it is an issue (at least, I think I am glad it is not my car or anyone else's -- just not glad it is happening).
This type of reduced charging rate has been happening to me off and on, as well, including today. I was charging at Dedham, MA supercharger, starting at a SOC of 19% or so. Had 100+ kw initially, but it dropped to 22 KW and stayed there once my battery charge was somewhere in neighborhood of 30%. I thought it might be because my battery got too hot, because the ambient temperature was 90F, and the AC fans had ramped up to be quite loud about the time that the current ramped down. So I was suspecting it was because of battery temperature.

 

[scaesare]

Had this happen again on my beach trip this last week, twice I think.

Both times I didn't drop quite as low as before (74A), but one around 55kW and the second about 40kW. The first time I let it ride, because by the time I noticed it, I had built up some SOC in the pack, and wasn't sire I wasn't just riding the charge curve.

The second time it definitely occurred, I dropped to ~40kW with only about 70 miles in the pack. I shuffled the car over a stall, and it ramped back up and seemed to stay OK.

One common denominator for me: this trip and my one several weeks go: I attempted to fire up the HVAC to keep the car cool initially, only to have the remote app report my SOC was too low. I had to wait until I got about 50 in the pack before I could turn it on.... anybody else?

 

[joebob73]

Similar issue happened to me while I charged in Fountain Valley, CA. There is a discussion in the California Supercharger thread hypothesizing that it is related to local utilities charging Tesla high rates during peak power usage. But upon hitting on this thread and seeing how wide spread the issue is, I'd bet on the firmware problem as well.

 

[hybridbear]

The thing is that these incidents only occur at people's local supercharger

Issues for me happened hundreds of miles from home.

I had virtually the same thing happen to me on a road trip this weekend. Charged at 114 kW for about 5 mins, then amps dropped to about 60A and stayed there. Tried another stall, same deal except the amps fell almost immediately.

The issue was Range Mode: If you leave range mode turned on, the forced cooling fans do not run -- the car attempts to cool everything through the passive radiator, and that's not enough on a hot day. The charging rate will be limited due to high battery temperature.

The next day I turned range mode off and charged at the same supercharger and everything was fine.

I had the charge power reduction with the fans running. Seems to be a supercharger issue. Changing stalls usually worked. I didn't track it enough along my road trip last month, but I feel like all the slow stalls were ones far away from the fenced in transformers or whatever they are inside the fence.

 

[FlatSix911]

It appears that Tesla has removed the Volts/Amps information on the Supercharging screen with release 8.0.
Sounds like they really want to avoid complaints about slow charging rates at SCs.

They F**kin' took the amps and volts off the IC and CID when supercharging! It was in the Beta, but now it only shows mi/hr, kWh, and kW. No amps. No volts