Charging Issue Level 2 at Home

[CoachK]

So I’m seeing 3 M3 AWD LR and 3 M3 RWD LR and 1 Y from 2018 and 2019

Another M3 I don’t know the detail about, for a total of 8 vehicles.

There are also 2 users who have M3’s having reduced amps received during charging. I wonder if this is related.

Any guess how many that might be all together since many are not on this forum or folks who aren’t aware because they use 110V or SC routinely who haven’t discovered it?

I think it’s hard to say since it depends on the quality of electricity each owner is receiving.I travelled to someone’s wall charger about 6 miles away by a condo complex and my M3 charged at 48 amps with no issue. So the owner there is having no issues. I do think since service is trying to find a fix I would assume it’s wide spread.

Right now our 2020 MY LR AWD is charging at 16amps and 240V on our home wall charger.

 

[vanzandtj]

My car (2019 M3 AWD LR) has charged normally three times in a row following the update to 36.11. I have a 14-50 outlet, and have configured a 31A limit. I've noticed that on the initial current ramp, it briefly draws 32 or even 33A before settling back to 31A.

I still think they're trying to detect the voltage drops due to overheating wiring or connections, and are getting false alarms due to changing loads elsewhere. It would be okay if they'd just revert to the "initial connection" state. Nobody would even notice. But requiring manual intervention is bad. And refusing to draw more than one or two amps is even worse.

 

[RheesB]

I had a FM radio failure on a update last winter. Then I had complete HVAC failure after another. Now, after another one in August we started with intermittent charge interrupted and now that's all we get on 120v or 240v (unless we are on our generator). I will be waiting on the upgrades after this.

 

[kjotwani]

Have a M3 MR RWD with Gen3 wall connector. was able to charge at 32A past few months. Since past few days the car is charging at only 6A. I’m unable to reset the wall connector nor force it to broadcast the SSID to check if it’s configured fine. Or is the issue with the car.

Anyone know how to reset the Gen3 Wall Connector to force it to broadcast its SSid

 

[vanzandtj]

Have a M3 MR RWD with Gen3 wall connector. was able to charge at 32A past few months. Since past few days the car is charging at only 6A. I’m unable to reset the wall connector nor force it to broadcast the SSID to check if it’s configured fine. Or is the issue with the car.

Anyone know how to reset the Gen3 Wall Connector to force it to broadcast its SSid

From the manual (e.g. https://www.tesla.com/sites/default...ng/Gen3_WallConnector_Installation_Manual.pdf):
"A unique SSID Wi-Fi network name and WPA2 password for connecting to the Wall Connector are printed on a label at the rear of the main unit, as well as on the front cover of the Quickstart Guide included in the box."

 

[kjotwani]

From the manual (e.g. https://www.tesla.com/sites/default...ng/Gen3_WallConnector_Installation_Manual.pdf):
"A unique SSID Wi-Fi network name and WPA2 password for connecting to the Wall Connector are printed on a label at the rear of the main unit, as well as on the front cover of the Quickstart Guide included in the box."

Yup aware of that. But scanning the QR code is a no-go as the Connector itself isn’t broadcasting the SSID.

 

[Quorky]

Back in Brooklyn from Catskills and the car is charging fine here as well. More and more evidence that this is software related issue.

 

[DrZoidberg]

2018 M3P, same problem.
Mobel connector won't charge (0,1 amp) eventually the car said charging fault. It eventually worked last night on a 110 socket. Then I plugged it back into the 14-50 today and it ramped up to 32 amps just fine.
No previous issues for nearly 2 years.

 

[vanzandtj]

Yup aware of that. But scanning the QR code is a no-go as the Connector itself isn’t broadcasting the SSID.

It's possible to establish a wifi connection even if the wireless network is not broadcasting an SSID. See: https://kb.netgear.com/30740/How-do-I-connect-to-a-hidden-network.

 

[westie10019]

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.

I agree %100, poor or lose connections can make the average HOME DEPOT Electrician cry! Intermittant problems with Ckt breakers can be just as difficult to find. The first thing to look at is wire connections. Make sure ALL wire connections are tight, this includes the breaker, neutral buss and ground buss in the panel. Then check the outlet wire connections and make sure they are tight! If all the connections are tight, a new breaker is relatively inexpensive to replace. Start with replacing the breaker, its a cheap fix. If you are not familiar with these terms or your are afraid of opening the main panel, PLEASE call a Licensed Electrician! It is to easy to make the wrong move and get hurt or worse working on a live panel. Electricity is NOT a hobby, its a SKILLED Profession. Unfortunately as a firefighter I have responded to one to many calls where a untrained home owner was hurt or badly burned working with energized panels.

 

[mylesm260]

2020 Tesla 3, LR AWD, mobile charger, level 2, 20 amp (16 amp nominal draw) same issue.

120 volt, or 240 volt / 20 amp, mobile charger, 0/1/2 amps, about 10-20 minutes, AC charging failed.

Scheduled the service appointment, tech came, no problems, told me it's a known issue and should be solved with a software update.

I get that the general consensus here is "dirty power" but I'm still not 100% sure on how the power is "dirty".

First of all, I want to address some things I've read...

"if you plug your car in and your lights dim you might have a bad ground"

no, no no, that is totally wrong.

Ground is not part of any circuit, it's not supposed to be. Therefore it will have zero effect on any line (hot - hot or hot - neutral) voltage anywhere in your house.

Ground is used for 2 main reasons, #1 safety, and #2 devices having the same reference voltage.

in some cases, a transformer (like inside a power supply for example) can induct some voltage into a metal case. If the metal case is tied to ground, this voltage will be "bleed off", and the voltage potential of the metal case will be zero.


And of course, the obvious safety, by tying any and all metal that could become electrified by a wiring fault to ground, you remove the risk of shock, because the voltage potential of any person coming into contact with said metal would be equal to ground, so the voltage potential of "grounded metal" and "grounded human" is zero and therefore it is safe.


The transformer that powers your house (in single phase power) has 2 wires on the high voltage side (usually 7.2KV where I live) and 3 wires on the low voltage side.

The "center tap" of the transformer is tied to ground, and this becomes your neutral. So neutral should always = ground.

So the wires leading to your house (if we freeze the AC wave in time) have a voltage potential of -120 volts, 0 volts, and +120 volts

Hot to neutral = 120 volts
hot to hot = 240 volts


I also take exception to the notion that the tesla is testing the ground by running any kind of current to ground.

Consider this: Many of our EV's are plugged into GFCI plugs / circuits with GFCI breakers.

a GFCI breaker is connected inside your breaker panel to the neutral and the hot bus(es), but NOT to ground. the ground wire is connected directly to the ground bus.

so if ANY current from a GFCI circuit is passed to ground, EVEN IF it's the ground wire FROM THAT CIRCUIT, the GFCI breaker will trip.

(if you don't believe me, go youtube search a video of a gfci plug being tested, it has 3 pins connected to the gfci plug, neutral, hot and ground, when you press the button to test the gfci, where is it bleeding the current off to? it can only be that circuit's ground pin, and those gfci testers are calibrated to test to "low threshold" of a gfci, about, 4-5 millamps)

AND, because there is no neutral on the level 2 connections, there is no way to check the ground reference (To check if neutral and ground are the same)

So effectively:

-The charger can measure the voltage from hot to hot (240 volt) or hot to neutral (120 volt level 1)
-The charger can measure the voltage from hot to ground, *HOWEVER* it can only measure this voltage by drawing a minute amount of current: any more than 4-5 milliamps (0.004 - 0.005 amps) will cause the GFCI to trip.
-Because there is no neutral on the 240 volt plugs the charger CANNOT MEASURE the voltage difference from neutral to ground.

Unless your ground is SO bad that it's equal to one of your hots (in which case you would have much much bigger problems), there really is no way for the tesla to test the ground, other than saying "look it's 120 volts from this hot to ground, and 120 volts from this other hot to ground"


So for these reasons, I don't think the issue has anything to do with a ground:

which basically just leaves the line voltage itself.

My thought at the moment are this:

In most cases, multiple houses share a single transformer, so looking around my street, I think my setup is:

7.2KV to transformer
-120 / 0 / + 120 to 4 houses

each house has a 100 amp service (mine does, so I'm guessing my neighbors do as well)

We're all trying to charge our cars when we get home from work. but this is also when our neighbors are cooking their dinner, doing their laundry, etc.

And because everyone using the same transformer is constantly changing the load, the voltage is varying slightly.

I think the tesla charger is looking for something like "30 seconds of stable voltage" and instead it's seeing 234, 238, 241, 239, etc etc and it refuses to charge.

This would also explain why when testing it at public chargers and at condos (where electrically, things are much more dense) has more success. Instead of having 4 households sharing one transformer, where a single dryer or range or hot tub turning on or off can cause a relatively large swing in voltage, you have a much larger transformers servicing many more households where a single device turning on or off has virtually no relative effect.


Does anyone remember the days of incandescent light bulbs?
Does anyone remember the lights in their houses dimming slightly for no reason?
I distinctly remember years ago, when my neighbor would turn on his table saw, even though it was only 120 volts / 15 amps, and even though we were in different houses, the inrush current of turning it on would be enough to sag the voltage of the all the houses using that transformer, if only for the half second it took for the motor to start to spin up.


One way to test this theory (and I will be testing this myself) is... Try to plug in the car just before you go to sleep, as late as possible, when most of your neighborhood is likely asleep, with their stoves and their dryers off for the day. If I'm right, we'll have more success then than we do at 5-7 PM.

 

[mylesm260]

As time has gone on it has stopped charging altogether.

So, I installed a 240V 30A receptacle and it still does not charge off of the local utility. But, here's the fun part, we have a 30 year-old 8kW diesel generator that runs the house through a transfer switch and the car charges just fine off of the generator! Same volts, same Hz, and the generator feeds the place through all of the same breakers and panels the utility power does.

I think this pretty much answers all the questions.

This isn't a ground issue, or a bad breaker issue, or a loose connection issue..

This is a software / source power issue for sure.

While RheesB's diesel generator may be old, if it's running at the correct RPMS (and given that's it's 8KW, it's most likely high end enough to have precise RPM control), it can generate a perfect, consistent 60hz pure sine wave.


I honestly think the problem is as follows:

many households share transformers, and many runs into particular neighborhoods cover great areas with many draws, far away from the step down stations.

Some of these draws can be uneven throughout the sinewave. (pulse width modulated loads, certain inductive loads, etc)

so the sinewave available to the tesla starts to look less like a perfect sine wave, and more like a jagged saw blade.


Perhaps the engineers at tesla are trying to balance the safety of preventing fires from things like jackasses trying to charge their cars off 16 gauge extension cords and reliability of charging.

That might explain why this problem started with a software update (Them trying to make the cars safer) and now they're struggling to come up with a fix for the reliability that wont sacrifice the safety.

In any case, there's no point in us tearing into our breaker panels tightening screws, running new earth grounds, etc... none of that is the cause of these issues (I'm not saying poor connections, bad breakers and bad grounds aren't a thing, I'm just saying they're not THIS thing) believe me, I myself went over every fastener from my EV plug to my sub panel to my main panel to my main service, and checked everything with a multimeter.

Besides, if you look at the user manual PDF for the mobile charger, it has a light codes for over voltage, under voltage, bad ground, etc... and none of us are seeing those error codes...

This problem cannot be found with a multi-meter, so calling an electrician won't help either... this problem must be diagnosed with an oscilloscope.

 

[Misternt]

My issue started mid August and I had no issues before August. My car can charge fine at 16 amps but only occasionally will reach 32 amps.

Today my PCS was replaced as a fix. Plugged in at home and charged at 32 amps.Tonight I plugged in and received charging reduced error and could only charge at 16 amps.

It sounds like lots of people have the problem and I plan on waiting a bit before putting in another service ticket.

 

[pjensen]

This problem cannot be found with a multi-meter, so calling an electrician won't help either... this problem must be diagnosed with an oscilloscope.

Agree totally.

Another dirty power cause are a/c systems cycling on and off all summer. When the compressor comes on, it can draw 100 amps instantly (for a few seconds).

 

[mylesm260]

Here's a youtube video that I think might help shed light on the issue. (just to give everyone an idea of what actually might be the cause of this)

My T3 did eventually start charging last night, but it was when I plugged it in after midnight.

if my theory is correct, the power gets cleaner later at night, generally speaking.

I plan to borrow my friends oscilloscope this week, and post pictures of what the power looks like when the car refuses to charge vs what it looks like when the car does charge.


In that youtube video, the cleanest power he got (other than his grid power) was that honda generator.

Generating power from a spinning generator is actually the easiest way to get a correct sine wave, after all, it's how the utilities do it as well.


Basically, some of us are too far away from our substations, and our sine waves are too "elastic" from the main grid. Uneven loads on our leg off the substation are causing imperfect sine waves, and our Teslas, likely due to changes in the software, are just too sensitive to these imperfections.


Imagine there is a 300KV to 7,200V substation 5 KM from your house. The 7,200V run off that substation that powers your house also powers a commercial / industrial area.

Maybe one of those businesses is running a plasma cutter, or maybe a bunch of laundry driers with pulse width modulated heating element control.

These types of loads can cause the sine wave to "chop up", kind of the same way wind can cause the surface of a lake to become choppy.

The further away the load is from the substation, the greater the effect on the sine wave, because of the resistance in the utility wires.


The fix is either going to have to be a software workaround, or us proving to our utility companies that the power they are supplying us is "dirty" and hopefully them doing something about it.


This is still a theory, but hopefully once I get a scope setup, I can provide some more evidence. I feel the traditional "voltage drop", "resistance to ground", "bad breaker" theories have all been beaten like a dead horse here. Furthermore Tesla themselves are not accusing any of us of having wiring faults in our homes, but rather actually pointing to dirty power from the utility and software.

 

[Sans-gas]

Today I tried to charge at a Tesla Wall Charger in a town nearby. It worked fine!

I was already at 70% charge but received 209V 48A for 10kW charge to top off.

I still can’t charge with my mobile Tesla cable at home on our 240V 30A circuit.

 

[BaBang]

Today I tried to charge at a Tesla Wall Charger in a town nearby. It worked fine!

I was already at 70% charge but received 209V 48A for 10kW charge to top off.

I still can’t charge with my mobile Tesla cable at home on our 240V 30A circuit.

Have you tried reducing the max amps it pulls at home and see if that helps at all? I've found that if I reduce to 16A, it charges successfully the majority of the time but if I set to 32A, it charges successfully very rarely. For me, there doesn't seem to be any consistency with when it will successfully charge based on time of day.

 

[Ruffles]

+1 for the software issue. I opened a service ticket for my model Y doing the same thing. I should be (and have been) charging at 40 amps but lately its been 0/1 amps or 16 amps. I get charging reduced errors that suggest unplug/plug in again. Tesla said the following:

"I found that what you are experiencing currently is due to a known issue that is under investigation. The vehicle will show this fault when it senses distorted grid voltage from the outlet, it should charge fine at another location with better grip power and using DC charging like the supercharger or CHAdeMO. This will likely be fixed in future firmware that will be sent to your vehicle automatically when available."

I'm running version 202.36.12.

 

[Sans-gas]

I had not tried to reduce amps, but it does allow a charge. I reduced it to 16 then when successful I increased it to 20A.

I can live with 5 kW. Thanks!

 

[Sans-gas]

Here's a youtube video that I think might help shed light on the issue. (just to give everyone an idea of what actually might be the cause of this)

My T3 did eventually start charging last night, but it was when I plugged it in after midnight.

if my theory is correct, the power gets cleaner later at night, generally speaking.

I plan to borrow my friends oscilloscope this week, and post pictures of what the power looks like when the car refuses to charge vs what it looks like when the car does charge.


In that youtube video, the cleanest power he got (other than his grid power) was that honda generator.

Generating power from a spinning generator is actually the easiest way to get a correct sine wave, after all, it's how the utilities do it as well.


Basically, some of us are too far away from our substations, and our sine waves are too "elastic" from the main grid. Uneven loads on our leg off the substation are causing imperfect sine waves, and our Teslas, likely due to changes in the software, are just too sensitive to these imperfections.


Imagine there is a 300KV to 7,200V substation 5 KM from your house. The 7,200V run off that substation that powers your house also powers a commercial / industrial area.

Maybe one of those businesses is running a plasma cutter, or maybe a bunch of laundry driers with pulse width modulated heating element control.

These types of loads can cause the sine wave to "chop up", kind of the same way wind can cause the surface of a lake to become choppy.

The further away the load is from the substation, the greater the effect on the sine wave, because of the resistance in the utility wires.


The fix is either going to have to be a software workaround, or us proving to our utility companies that the power they are supplying us is "dirty" and hopefully them doing something about it.


This is still a theory, but hopefully once I get a scope setup, I can provide some more evidence. I feel the traditional "voltage drop", "resistance to ground", "bad breaker" theories have all been beaten like a dead horse here. Furthermore Tesla themselves are not accusing any of us of having wiring faults in our homes, but rather actually pointing to dirty power from the utility and software.