TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Car not charging using all Amps available

Discussion in 'Model 3: Battery & Charging' started by Gretaf, Oct 23, 2019.

  1. Gretaf

    Gretaf New Member

    Joined:
    Oct 23, 2019
    Messages:
    2
    Location:
    Boucherville
    Hi there

    Can’t see if someone already post about this.

    when I plug my Tesla 3 with Tesla wall connector, car will not use all 32 amps available, thus charging at 11km/h instead of 52km/h. As anyone experienced this?

    if I unplug and plug it again, one or two times, problem is fixed. But last night, everything was fine and used scheduled charging. But during the time, it went back to a lower charging speed.

    Went back to the car this morning. Unplugged the connector and plugged it again. Now it’s fine. Using 32 amps.

    Someone why I experience this??
    Thanks
     
  2. Wennfred

    Wennfred Supporting Member

    Joined:
    Apr 4, 2019
    Messages:
    1,451
    Location:
    San Diego
  3. jdw

    jdw Supporting Member

    Joined:
    Jun 1, 2015
    Messages:
    595
    Location:
    Montreal, Canada
    If not the above, it may just be that the line voltage sags while you are charging and the car automatically lowers the charge rate. It does that to avoid overheating anything or popping the breaker. The main reasons for voltage sagging during charging are insufficient supply to the electrical panel, insufficient wiring/breakers or a bad connection or socket. Try lowering the charge rate a few Amps at a time and see if there is a charge level that reliably works and troubleshoot from there.
     
  4. Gretaf

    Gretaf New Member

    Joined:
    Oct 23, 2019
    Messages:
    2
    Location:
    Boucherville
    It’s the four times I’m experiencing this.

    sometimes I just unplug connector 2-3 times and I’m ok. Charging level goes up to normal speed.

    I have left a message to my electrician.
     
  5. srs5694

    srs5694 Active Member

    Joined:
    Jan 15, 2019
    Messages:
    1,024
    Location:
    Woonsocket, RI
    On the car's screen, you can increase or decrease the amperage used to charge the car, within certain limits. (You can't raise it above what the EVSE is offering, for instance.) See if you can do this. The car is supposed to remember a changed setting in a geo-located way, so if you lowered it once, it should stay lowered at that location. It's possible that this is what you're seeing -- you may have accidentally lowered the charge rate and it "stuck" that way. If so, raising it on the screen should fix the problem.

    It's also possible that the car or EVSE is lowering the charge rate because it's detected a problem, such as reduced voltage or overheating of a component. IIRC, the car is supposed to display a message about such problems on the screen, but I'm not 100% positive of that. In any event, you should check your display and, if you see such a message, record exactly what it says and report it here. Some such problem might be correctable by an electrician; for instance, if a loose connection is causing overheating, then an electrician should be able to fix that problem.

    Also along these lines, try sitting in your car and watch the display for the first few minutes of a charge session. It should start at about 240v (plus or minus a bit) and stay pretty steady, with amperage that ramps up from 1A to 32A (if that's what your limit should be) within a few seconds. If it starts at 240v and 1A, but the voltage drops significantly (say, to 200V) as the amperage rises, then that indicates a wiring problem. Maybe the run is too long, or maybe the wiring is under-sized. In either event, the car will drop its amperage, since under-sized wiring might overheat, and perhaps cause a fire, when you try to draw too many amps.
     
  6. Rocky_H

    Rocky_H Active Member

    Joined:
    Feb 19, 2015
    Messages:
    4,291
    Location:
    Boise, ID
    "lower" doesn't tell us what is going on. How many amps exactly is it?

    If it's 16A or 24A, those are two different types of problem:

    16A is half of your 32A. The onboard car chargers have internal modules of 16A each. (Two of them for the 32A version) We've seen some issues when a car has a kind of defective charger that is going out, it will sometimes have one of the modules not working, and you get only half the charging speed.

    24A is three fourths of your 32A. The car has a safety monitoring system to look for excessive voltage drop in the circuit when it starts ramping up the charging. If it sees too much voltage drop, possibly indicating a loose connection, it will reduce to 3/4 of the regular charging current to see if that is more stable.
     
    • Like x 1
  7. tgposz

    tgposz New Member

    Joined:
    Jun 22, 2019
    Messages:
    2
    Location:
    Concord, CA, USA
    I had this problem in my 2018 model 3 after about 4 months of home charging, but my issue was at 40 amps with a JuiceBox. What happened in my case is the car was detecting some problem and lowering the amperage to 32 to complete the session. Sitting in the car, as suggested, revealed either a 0 to 40 amp ramp, then a few minutes later a charging error message and drop to 32 amps, or a 0 to slight ramp up to 6 or 8, then drop and a few repeat of ramping to 6 or 8, finally a message about a charging problem and it would then ramp up to 32. Tesla Service had to diagnose for a few days and finally replaced the charger in the car, no problems since.

    Picture is of the charging session from POV of the JuiceBox, scale is KV Screenshot_20181128-145411_EV JuiceNet.jpg
     
    • Informative x 1

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC