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“Unable to AC Charge”

I get the above message when I use my J1772-to-Tesla adapter at my friend’s house.

Her J1772 cable charges her Nissan Leaf just fine.

A public J1772 charging station using my adapter charges my Tesla just fine.

But using her cable and my adapter always immediately gives me the “Unable to AC charge” message.

Any debugging advice for me?

Comments

  • Sounds like her J1772 may not be standard and/or tuned to only work with the Leaf? Strange, but the fact your car works fine at a public J1772 reduces the likelihood that the Tesla is the problem source.
  • I agree with TeslaTap.com, her J1772 is probably not a full spec system. The Tesla does a handshake with charging systems and I'll bet the handshake is failing.
  • Would this happen if the Leaf system was set to charge at a lower amp rate and you had the Tesla set to charge at 32 Amps.
    At public charging station it adjusts it in case it's lower, but I don't know how it works at other places.
    If a person has a 80Amp setup for an old model S with dual chargers and the original version wall charger, would it work on a different model that doesn't take that much power?
  • My guess is that the ground, or the neutral for the outlet is not connected
  • The Tesla doesn't use or require the neutral for a 240VAC connection. A bad ground should trip a ground fault. With the Mobile cable and the HPWC it will explain a problem in English on the dash display. Not sure which if any J1772 problems can be detected/displayed.
  • Same issue here. 1st time trying to charge at a public J1772. It connects fine, I get a blue light but error message "unable to ac charge, try unplugging and replugging". Didn't help. Charger says "connected" but doesn't start. It was charging a leaf in the next space.
  • edited January 14
    > @dgb62 said: > I get a blue light but error message "unable to ac charge, try unplugging and replugging". Didn't help. Charger says "connected" but doesn't start. It was charging a leaf in the next space."

    Some chargers requires you plug in first, others that you open charging app first. I'd suspect just not following instructions for that device.

    On the home charger case, I'd plug into it, get the error and call Tesla Emergency number and the battery/charging submenu. They can look at the car in real time and might provide more details on the error.

    There's one video where guy goes around to public chargers with the Chademo adapter and can't charge does a series of YouTube videos.

    I told him about how to use the Chademo on connecting and retried and they all worked.
  • Unfortunately, public chargers, being built by many other companies, sometimes aren't fully interoperable with all cars.
    this is the curse of open standards. It is extremely hard and expensive to make every one work with every car.
    I recommend looking at plugshare.com for another nearby public charger and trying it out.
    BTW, what brand is the J-1772 charger that isn't working?
  • If the EV connector unit is not wired with a proper ground/neutral it could give an error as well
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