Model S

Charger "Starting & Stopping" When Reaches Max Threshold

For the past two weeks when my 2019 Model S Long Range reaches the maximum charging threshold there's a constant "start and stop" of the charging. The Wall Connector makes the same "clicking" noise it does when charging begins under normal circumstances.
If I open the door of the car when this is happening the "start and stop" charging stops. I have reduced the amps well below 48 amps which doesn't make a difference. Have also ensured the cable is off the floor of the garage to avoid colder temps on the cable. Has anyone experienced this and determined the solution to resolve or do I need to take my car to a Service Center?
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Comments

  • I've not encountered it. What is your threshold set to? If 100%, you might try a lower SOC threshold, as 100% is not recommended except for trips where you need it.
  • Thanks for your reply. Experiencing issue with max threshold set anywhere between 50% - 70%
  • Always try a reboot when things go awry.
  • Should've mentioned that. Have rebooted the car and the charger
  • I had exactly the same issue last weekend with my 2015 85D at my vacation home. Charge level was set to around 70%. Rebooted both my OpenEVSE charger and the car. Problem went away but it happened again the next day. Temperature was near the freezing mark, car parked outside. Now that I'm back at home it hasn't happened again. Firmware 2020.36.3.1.
  • @Bitjockey interesting. I'm on 2020.40.4 but sounds like the same issue. I'm going to keep tinkering around this weekend. If problem persists I'm going to schedule something with service. Will report back if I learn anything meaningful
  • What’s the periodicity of the stop-start cycle?
  • @Bighorn start-stop cycle happens indefinitely until I open the door of the car or unplug. Has happened each time I've reached max threshold over the past couple weeks. Has gotten a little colder where I'm at but not below freezing and I didn't experience this all of last winter with plenty of days below freezing
  • Right, but how quickly does it cycle? Every few seconds or 15 minutes?

    It used to be that a replenishment cycle after reaching goal didn’t happen until there was a 3% loss. I believe that’s changed to where it re-ups much earlier. So I’m wondering if it’s a BMS glitch or there might be a big draw that is triggering a threshold re-charge cycle. Do you have big consumers checked like Sentry and Summon standby would be follow on questions if the cycling is not that frequent.
  • Misunderstood your original question. It happens every few seconds. No battery consumers enabled when this occurs
  • Gotcha. Sounds bad. They may be able to diagnosis remotely. And possibly fix at your place.
    If you had a supercharger nearby, you could get another data point for narrowing the diagnostics.
  • I have the same problem with my 2020 S LR purchased in June.
    It started about two weeks ago. Prior to that I didn't have this problem. I get the "charging interrupted" message multiple times in the day after charging is completed. I have a NEMA 14-50 circuit I've been using since getting my 2014 S. I haven't seen charging interrupted before it has reached the charging set point. No problem at Superchargers. As long as it charges, it's just a nuisance from the app so I haven't contacted Service yet. Hoping the next update will clear this up since it seems to have been a M3 problem that was fixed by an update.
  • I've been having this problem for at least the last 6 firmware releases (on 2020.40.8 presently) and have studied it a bit. I've a 2019 MS Long Range. It happens both with my HPWC (48A/244V) and my Mobile Unit (using both 12A/122V and 24A/244V), so the fault apparently lies with the car. I have data on all three charging combinations that include 'starting', 'stopping', 'elapsed' and 'since last start' times, using a motion detecting camera to monitor either the HPWC's or the Mobile unit's moving "green" stripe. After numerous back and forths with Tesla, they appear to have decided that such behavior isn't correct and have set me up with a service appointment in two weeks. Generally, with the charge limit set at 80%, it would cycle about every 16m50s and last from between about 17s up to 35s or so. There were sequences that didn't follow that exactly, but those were the majority. Not once did the app ever notify me that charging had commenced.
  • > @btlalum said:
    > I've been having this problem for at least the last 6 firmware releases (on 2020.40.8 presently) and have studied it a bit. I've a 2019 MS Long Range. It happens both with my HPWC (48A/244V) and my Mobile Unit (using both 12A/122V and 24A/244V), so the fault apparently lies with the car. I have data on all three charging combinations that include 'starting', 'stopping', 'elapsed' and 'since last start' times, using a motion detecting camera to monitor either the HPWC's or the Mobile unit's moving "green" stripe. After numerous back and forths with Tesla, they appear to have decided that such behavior isn't correct and have set me up with a service appointment in two weeks. Generally, with the charge limit set at 80%, it would cycle about every 16m50s and last from between about 17s up to 35s or so. There were sequences that didn't follow that exactly, but those were the majority. Not once did the app ever notify me that charging had commenced.


    Nice data. Did you happen to observe whether the rated range or SOC% dropped when the charging started back up? The thought of a recent FW glitch is sort of shot if you’ve had this for several earlier iterations.
  • In all the cases that I checked, the SoC% was always 80. The observations were all in my garage and Sentry Mode and Maintain Cabin Temp were always off. When the car is unplugged, the SoC generally drops by <1%/day. I last drove it >48 hours ago, and the SoC was 77% when I parked it, and is 76% now.
  • Oh, and there are no third-party app's active, either...that's been posited a few times (particularly by Tesla) as the issue. It's not, at least in my case.
  • Certainly needs addressing and hopefully it is a readily apparent fix. Until then, some creating charging strategies are in order. Just spitballing, fewer plug ins and using scheduled charging to barely finish before it’s time to leave. Of course, during covid many people are mostly parked, so could remain unplugged for long periods.

    @btlalum Have you assessed supercharger behavior?
  • I've used several but have never reached full charge percentage and then continued to sit there to see if it starts/stops the way the AC charging does....don't have one really close and am generally traveling when I do use them, so not much interested in "diagnosing"! Perhaps I will drive to the closest and sit for an extra 1/2 hour to see if it starts up again, just for completeness.
  • Good point. I was thinking the cycling was more rapid based on first impressions.
  • I did the SC test...sat for 35 minutes after charging finished, but it never restarted. That said, using the AC methods, sometimes it would start cycling within 35 minutes after completing its charging--but not always. Sometimes it would take 2+ hours. Didn't want to sit there all afternoon. :smile: I'll post again after the service center has a look at it. That's not until 11/19, however.
  • I like the cut of your jib 🧐
  • I have had the same problem for two weeks with my Tesla 85D 2015 version 2020.36.3.1. have you had any solution from Tesla? my appointment is only at the end of the month 🙁
  • @btlalum curious if you had your appointment yesterday. If so, what was the outcome? Thanks in advance
  • > @walshda82 said:
    > For the past two weeks when my 2019 Model S Long Range reaches the maximum charging threshold there's a constant "start and stop" of the charging. The Wall Connector makes the same "clicking" noise it does when charging begins under normal circumstances.
    > If I open the door of the car when this is happening the "start and stop" charging stops. I have reduced the amps well below 48 amps which doesn't make a difference. Have also ensured the cable is off the floor of the garage to avoid colder temps on the cable. Has anyone experienced this and determined the solution to resolve or do I need to take my car to a Service Center?

    I am having the same problems with my Model X. 6 month ago we noticed that after the car was charged to about a 75% set point, the charger would turn off for 15 minutes, then on for 45 second. It never did this for the first 2 years we owned it. The car would keep cycling like this until we opened the app and told it to "Stop Charging". We tried all the car resets (thumb wheels and emergency shut down and restart) and these had no impact on the problem. The problem is with the car not the charger as the car controls the charger. We have a second home with the exact same charger and it does the same thing there also. I'm thinking it is a software problem. We found that we could use the app to increase the charging level, then cancel the charging, and that would get the cycling to stop. Two days ago the problem changed where it now cycles 3 seconds on, 3 second off after reaching the charging set point. (We are charging to 210 mile on a 100D with a 280 mile range.) I just talked to Tesla support again (they are always REALLY nice), and they suggested having a mobile service technician come out and they should be able to diagnose the problem. Excellent idea as I can easily set the car up so the charger will be cycling when they arrive. If I can find my way back to this page I'll let you know what I find out. Otherwise you can text me at 925-446-1084.
  • > @walshda82 said:
    > @btlalum curious if you had your appointment yesterday. If so, what was the outcome? Thanks in advance

    Hi...sorry to be slow in responding!

    Yes, I had my appointment, and basically they claimed they couldn't reproduce it, said it "might be" noise on our home power line, leaving me to deal with their having factory-reset the thing, wiping out all I had stored (fortunately, they did remove the USB drives...whew). I got the car home and sure enough, it does exactly as it was doing before....about 16m50s and then charges for 25 or so seconds.

    I'm guessing that they didn't leave it long enough, nor perhaps monitor it closely enough, to see the events. When I got the car home, I charged it to 80%, having already setup my motion-detecting camera. It was 4h14m41s before it began to charge again, and that time charged for 159 seconds. Then, 27m10s later, it began to charge again, this time for 27s. After that it got back into the 16m50s routine with about 24-25 seconds of charging.

    Interestingly, I was loaned a '15 S 85D, so I gave it the same examination. It took 20h43s to start charging again, once it had reached the setpoint of 75%. After that, the recharges happened hours, not minutes apart. The data below show this: it was taken over the period 11/20 into 11/22. Clearly a different behavior, which to my way of thinking obviates their "powerline noise" hypothesis. Bottom line, still don't know!! It is interesting to note that late at night, charges occurred that were LESS than an hour apart (@ 22:30:17 and 23:56:56)...don't have any idea if that's significant or not.

    Start Finish Time since Charge
    Last Charge Duration
    12:35:41 12:36:18 20:00:43 37 This was the first charge after the 85D had reached its 75% setpoint.
    15:25:10 15:26:37 2:49:29 87
    18:48:20 18:49:49 3:23:10 89
    22:06:51 22:08:18 3:18:31 87
    22:30:17 22:30:37 0:23:26 20
    5:02:52 5:04:59 6:32:35 127
    9:25:02 9:26:58 4:22:10 116
    13:18:03 13:19:50 3:53:01 107
    16:24:23 16:25:48 3:06:20 85
    19:49:54 19:51:25 3:25:31 91
    23:15:59 23:17:29 3:26:05 90
    23:56:56 23:57:08 0:40:57 12

    The following are the data from my 2019 S Long Range, after getting it home and updating to 2020.44.15 firmware:

    17:19:29 17:22:08 4:14:41 159
    17:46:39 17:47:06 0:27:10 27
    18:03:31 18:03:56 0:16:52 25
    18:20:22 18:20:44 0:16:51 22
    18:37:03 18:37:26 0:16:41 23
    18:53:45 18:54:09 0:16:42 24
    19:10:36 19:10:59 0:16:51 23

    Afraid I can't shed much light on the issue, but the fact that many of us are having the same issue might mean(?) that it's firware-related?

    Love to hear other thoughts!

    Cheers!

    P.S...sorry the formatting doesn't remain fixed once it's posted. :-(
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