Charging Issue Level 2 at Home

[jim_p]

Upon arriving home a week ago Friday, I plugged in my level 2 charger and the car would show charging, but it would only draw between 0-2 amps, flashing green, but staying at 0 mi/hr, then after about 5 minutes, the light on the charge door turns red and the message comes up "Unable to AC Charge - unplug and retry. I rebooted the car, soft/hard, put to sleep, no change. I use a 3rd party(Openevse 40A)n j1772 with the adapter, tried different adapter, no change. Tried tesla mobile charger, same reaction. The next morning, I had an electrician come check the electric and everything was ok, Since he was there, I did have him rewire the circuit (#6 wire about 1' from the panel) and install a 50 amp breaker and change the 15-40 outlet so I could charge at a faster rate, if needed. After he was done the car charged at 240v/32 amps and I thought everything was ok. That night, I tried to charge and the same thing that happened originally, 0-2 amps then error. I've tried 2 different chargers at 240V both do the same thing. The car will charge on the 120 V mobile charger without issue and supercharges without issue. I also tried at another location a level 2 running at 210V/48A and it charged without issue.

I did update to 2020.36.3.1 the morning of the night it started and have since updated to 36.10 with no change,

Since then it will charge occasionally, if I stop and start charging maybe once every 30 times I do it, usually I just give up trying. Once it starts, it will charge without issue, but if I stop in the middle and restart charging, it will go back to error status. Even when it does charge, it sits in that 0-2 amp (sensing I imagine) for at least 30 seconds before it ramps up. It usually would do the 0-2 for 2 seconds then ramp up to full charging.

2018 Model 3 LR RWD 13k miles.

Tesla is looking into it, but this department only works M-F, I haven't been able to find any similar threads anywhere, any ideas what the issue may be?

 

[GigaGrunt]

What’s the voltage it shows? M3 is very sensitive to varying voltage. This can be caused by loose connection at 14-50, bad breaker, etc. Seems that the higher amp load is where the issue is. I’d have the wiring and breaker all verified. Even if it’s new. Alongside that, continue to have Tesla look into. Potential that PCS is faulty. Supercharging should work and have zero affect as AC charging uses different hardware than DC charging/Supercharging.

 

[jim_p]

Thanks for the quick reply. It appears to have started right after the summer heat subsided in CT. The car shows between 244-247V when it's sensing. If it does actually start charging, it usually drops to around 237V.

I'll have them come out and check the wiring again.

 

[AlanSubie4Life]

Thanks for the quick reply. It appears to have started right after the summer heat subsided in CT. The car shows between 244-247V when it's sensing. If it does actually start charging, it usually drops to around 237V.

I'll have them come out and check the wiring again.

Could be the car, could be the OpenEVSE.

I’d see if you can borrow the 14-50 adapter for the UMC from another owner (or purchase it - seems like you could use it as a backup anyway and it is good to have), and try the UMC. (Unclear...You said “change the 14-50 outlet”...not clear to me what outlet you currently have installed...)

If you still have a 14-50 outlet and can do this experiment, and that works reliably with the UMC, I would suspect the OpenEVSE of course.

Weird though.

I don’t think that voltage drop you are seeing is an issue. It’s not from the wiring from the panel to the car - too short - most likely that drop is from the service connection. In any case that 9V drop is fairly typical for a 32A draw in the case of a service connection that is not super robust.

I see about the same drop (at 40A) and I have never had any problems.

I guess you could have them check for upstream wiring issues. Make sure the ground is very solid too (though it won’t charge at all if that is open or fairly high-Z, as I recall)

 

[jim_p]

Could be the car, could be the OpenEVSE.

I’d see if you can borrow the 14-50 adapter for the UMC from another owner (or purchase it - seems like you could use it as a backup anyway and it is good to have), and try the UMC. (Unclear...You said “change the 14-50 outlet”...not clear to me what outlet you currently have installed...)

If you still have a 14-50 outlet and can do this experiment, and that works reliably with the UMC, I would suspect the OpenEVSE of course.

Weird though.

I don’t think that voltage drop you are seeing is an issue. It’s not from the wiring from the panel to the car - too short - most likely that drop is from the service connection. In any case that 9V drop is fairly typical for a 32A draw in the case of a service connection that is not super robust.

I see about the same drop (at 40A) and I have never had any problems.

I guess you could have them check for upstream wiring issues. Make sure the ground is very solid too (though it won’t charge at all if that is open or fairly high-Z, as I recall)

I have the 14-50 adapter, it doesn't appear to matter if I'm using the umc or the open EVSE the umc shows exactly the same.symptoms.

 

[AlanSubie4Life]

I have the 14-50 adapter, it doesn't appear to matter if I'm using the umc or the open EVSE the umc shows exactly the same.symptoms.

Ok.

Given it seems to work fine elsewhere (how many other places/times have you tried?), it does seem less likely to be the car...

Sounds like a new outlet...so presumably no problems there...so I guess I would have them look for weird wiring problems, like a bad ground. Be sure that the neutral and ground aren’t shared, the ground is properly grounded at the panel, etc.

I suppose it could be something about the voltage drop but like I said that seems pretty typical.

 

[GigaGrunt]

In my old house, I had a 14-50 installed. I would plug in M3 and screen would show 243V initially. After the initial charge rate would increase from 1/32A to around 26-27A, the voltage would drop to 235-237V. It would reach 32A, then M3 would either reduce charging to 12A, or stop completely. This was due to faulty wiring install/loose connectors. Happened within 3-4 days of plug install. After a quick check and tightening of connectors at breaker and plug, issue went away.

 

[MOMedic82]

Upon arriving home a week ago Friday, I plugged in my level 2 charger and the car would show charging, but it would only draw between 0-2 amps, flashing green, but staying at 0 mi/hr, then after about 5 minutes, the light on the charge door turns red and the message comes up "Unable to AC Charge - unplug and retry. I rebooted the car, soft/hard, put to sleep, no change. I use a 3rd party(Openevse 40A)n j1772 with the adapter, tried different adapter, no change. Tried tesla mobile charger, same reaction. The next morning, I had an electrician come check the electric and everything was ok, Since he was there, I did have him rewire the circuit (#6 wire about 1' from the panel) and install a 50 amp breaker and change the 15-40 outlet so I could charge at a faster rate, if needed. After he was done the car charged at 240v/32 amps and I thought everything was ok. That night, I tried to charge and the same thing that happened originally, 0-2 amps then error. I've tried 2 different chargers at 240V both do the same thing. The car will charge on the 120 V mobile charger without issue and supercharges without issue. I also tried at another location a level 2 running at 210V/48A and it charged without issue.

I did update to 2020.36.3.1 the morning of the night it started and have since updated to 36.10 with no change,

Since then it will charge occasionally, if I stop and start charging maybe once every 30 times I do it, usually I just give up trying. Once it starts, it will charge without issue, but if I stop in the middle and restart charging, it will go back to error status. Even when it does charge, it sits in that 0-2 amp (sensing I imagine) for at least 30 seconds before it ramps up. It usually would do the 0-2 for 2 seconds then ramp up to full charging.

2018 Model 3 LR RWD 13k miles.

Tesla is looking into it, but this department only works M-F, I haven't been able to find any similar threads anywhere, any ideas what the issue may be?

I actually have been having almost the same issue! After 9 months + of perfect charging with my Mobile Connector and 15-40 outlet, my car would not charge. Charger lit up like it was charging (flowing green lights) and the charge port showed flashing green (until sometimes it would turn red after about 30 mins). The screen showed that it was charging and would give an eta to completion. Showed the voltage (235-249) and amps at 0-2 with no miles added per hour. I took the car to Tesla and they said there were no issues they could find. The car charged fine at Supercharger and on chargepoint stations. Tesla replaced my mobile wall connector and I had no issues at home charging. Then, 3 weeks later, same problem. Like you, my mobile wall connector worked fine on the 110 plug at home. Also, the loaner model s charged on the 15-40 plug at my home with no issues. The service center says there's no problems with the care and sent me on my way. I have been intermittently able to charge at home with my MWC and 15-40 plug. I put a call into Tesla Customer Support and they have escalated the issue and I'm waiting to hear back.

Also, I have had the electricians back out to verify all components as well as had the electric utility do line voltage verification...all of which came back perfect.

 

[jim_p]

At least I'm not the only one having this issue, I am also waiting for Tesla to get back to me, I'll post an update when available.

Makes it tough to have an EV when you drive 120 mi/day and can't predict whether you'll be able to charge when you get home.

With so much technology, curious that the car doesn't say why it won't charge.

 

[jim_p]

Ok.

Given it seems to work fine elsewhere (how many other places/times have you tried?), it does seem less likely to be the car...

Sounds like a new outlet...so presumably no problems there...so I guess I would have them look for weird wiring problems, like a bad ground. Be sure that the neutral and ground aren’t shared, the ground is properly grounded at the panel, etc.

I suppose it could be something about the voltage drop but like I said that seems pretty typical.

I only tried 1 time at another location (level 2 AC). But I did try another model 3 at my house and it would only charge at a reduced rate 16A/32A so I assume the cars aren't liking something that my electric is/isn't providing. Just wish it could tell me.

Having an electrician come and replace the sub panel (old) that feeds the outlet to see if that makes a difference.

 

[AlanSubie4Life]

Having an electrician come and replace the sub panel (old) that feeds the outlet to see if that makes a difference.

Seems likely this could help. I doubt replacement is necessary (but it depends!), but my guess is there is an issue with the grounding somewhere...it's also possible the breakers are crappy, etc. - but I doubt it, since the voltage drop seems ok and the run is short.

Again, make sure the electrician checks for solid ground continuity all the way back to the main panel bond to ground! The line voltages appear to be mostly fine already - but if there is a ground bond in the sub panel, and it's a separate ground relative to the ground for the line voltages, the UMC may detect this as a high ground impedance, even if the grounding in the sub panel is actually fairly solid. The UMC injects a bit of current from the line voltage into ground, to check the impedance between the ground and the ground for the line voltage.

If the grounds are separate (meaning there is not a direct wired ground connection from the sub panel ground to the main panel ground), for the circuit to complete, this test current would have to travel from the subpanel ground back to the main panel ground, through who knows what path (the earth, probably). That could easily be detected as a high impedance, I think. You cannot use the earth as a conductor. That could also explain why it's getting worse now - the impedance of the earth could be increasing as things dry out, or get cooler, etc.

That's my guess, and I'm sticking to it! I'm just a guy on the internet, though.

Doesn't really explain why the OpenEVSE doesn't work though (or misbehaves in the same way). Maybe the car does some checking of the quality of the ground too? No idea.

 

[Sans-gas]

Have you gotten any resolution to this problem?

My 2019 M3 LR LWD is going into svc center tomorrow for this same issue. I’m hoping they don’t say “can’t duplicate your problem, it’s on your end”.

 

[jim_p]

Have you gotten any resolution to this problem?

My 2019 M3 LR LWD is going into svc center tomorrow for this same issue. I’m hoping they don’t say “can’t duplicate your problem, it’s on your end”.

Nothing yet, my thought is the charging system has become sensitized to incoming voltage and it won't engage the charger, not sure of the why, I'll will post updates as they happen.

 

[AlanSubie4Life]

Upon arriving home a week ago Friday, I plugged in my level 2 charger and the car would show charging, but it would only draw between 0-2 amps, flashing green,

2018 Model 3 LR RWD 13k miles.

After 9 months + of perfect charging with my Mobile Connector and 15-40 outlet, my car would not charge.

My 2019 M3 LR LWD is going into svc center tomorrow for this same issue.

With three separate reports from vehicles & charging setups that apparently were previously fine, I'm beginning to suspect a software issue. When did each of you encounter this problem, and was it correlated with a software update?

EDIT:
(Make that 4 - see below...)

 

[vanzandtj]

I've had similar problems lately.

I have an M3 AWD LR, manufactured in April 2019. I charge it in my garage with a UMC plugged into a professionally installed NEMA 14-50 outlet on a dedicated circuit (6 awg copper wires) with a 50A circuit breaker. There's nothing else on that circuit. I don't have electric heat, hot water, or clothes dryer. The biggest load is the electric stove. The UMC is mounted in a bracket that takes all the weight off the outlet. The on-board charger is set for charging to 77% and drawing up to 31 A.

I've been using this setup for over a year with no issues, but recently I've had:

- Slow charging. The current draw cycles between 0 and 1 A, increasing to 2 A only briefly starting after one minute and again every minute or so after that.

- Interruption. I get a text message like "charging interrupted at 9:29 with battery at 194", a message "Unable to AC charge. Disconnect and retry" on the console, a red light at the charge port, and the "TESLA" lights on the UMC lit solid green. Disconnecting and reconnecting will restart charging. This happened first on 8/29. I don't think I'd ever seen a red light at the port before then. Now sometimes it happens several times a day.

- Stopped charging. The "TESLA" lights on the UMC were solid green, and there was no light on at the charge port. I opened the driver's door, the display woke up with "starting to charge", and charging resumed. (This is like normal charge completion, except it hasn't reached the target capacity.) In the last two hours, it's made no progress at all. It's stopped at 6:49 (38%), 8:22 (38%), 8:59 (37%), and 9:12 (37%). Twice it restarted when I just opened the car door. The other two times, I disconnected and reconnected.

I've still never seen a red light on the UMC. The garage is cool (~60 F). Things I've tried:

- Resetting the circuit breaker.
- Restarting the console using the two steering wheel buttons.
- Power cycling the car by navigating safety & security > power off.
- Unplugging the UMC from the outlet and reconnecting.
- Unplugging the UMC, unplugging its NEMA 14-50 pigtail, and reconnecting.
- During one of the periods it was drawing significant power (16A or 31A, I don't remember), I stopped charging, pulled the breaker, opened the outlet, and felt around. Nothing was warm.

The software was updated to 2020.24.6.9 on 7/22, to 2020.28.6 on 8/6, and to 2020.32.3 on 8/31.

I suspect one of the software updates made the charger more sensitive to voltage surges or sags - especially since others are now reporting the symptoms.

 

[vanzandtj]

I just got another alert - charging stopped at 9:30 (37%).

 

[AlanSubie4Life]

2020.28.6 on 8/6, and to 2020.32.3 on 8/31.

This happened first on 8/29.

Hmm. That is hard to explain.

I just got another alert - charging stopped at 9:30 (37%).

Very safe!

 

[jim_p]

My issue started on 9/11, that morning I updated to 36.3.1, that night it started, was fine up until then.

 

[GigaGrunt]

What type of EVSE is everyone using?

 

[CoachK]

I actually have been having almost the same issue! After 9 months + of perfect charging with my Mobile Connector and 15-40 outlet, my car would not charge. Charger lit up like it was charging (flowing green lights) and the charge port showed flashing green (until sometimes it would turn red after about 30 mins). The screen showed that it was charging and would give an eta to completion. Showed the voltage (235-249) and amps at 0-2 with no miles added per hour. I took the car to Tesla and they said there were no issues they could find. The car charged fine at Supercharger and on chargepoint stations. Tesla replaced my mobile wall connector and I had no issues at home charging. Then, 3 weeks later, same problem. Like you, my mobile wall connector worked fine on the 110 plug at home. Also, the loaner model s charged on the 15-40 plug at my home with no issues. The service center says there's no problems with the care and sent me on my way. I have been intermittently able to charge at home with my MWC and 15-40 plug. I put a call into Tesla Customer Support and they have escalated the issue and I'm waiting to hear back.

Also, I have had the electricians back out to verify all components as well as had the electric utility do line voltage verification...all of which came back perfect.

We are experiencing the same issue. We have charged with the Tesla Wall Connector for 16+ months with no issues. Last week we similarly saw voltage (244-247) and amps 0-3 and no miles added. We also have a 2020 Model Y with the same issue. We tried the Mobile Connector into a 120 wall outlet and that had the same issue. We took the wall connectors to the Tesla Service center and they worked there and charged the car with 125v and 12amps. We had an electrician come and he checked outside voltage coming in, voltage in the Wall Connector etc and all was fine.

We went to our neighbors house and connected via the Mobile Connector and saw the same issue. Wondering if we are getting dirty/fluctuating voltage from the power company in our neighborhood that is causing the issues?