Charging Issue Level 2 at Home

[Sans-gas]

I originally felt the ability to charge was linked to time of day, though there was no scheduling set on the car. For the first 2 weeks I was ALWAYS able to charge between 8 and 9 AM, but never after 10pm.

Now, except when reducing amps, I can’t charge anytime.

No AC issues here, since it’s not hot, not cold regionally. No industry around to explain uneven (dirty) power delivery.

 

[Quorky]

I originally felt the ability to charge was linked to time of day, though there was no scheduling set on the car. For the first 2 weeks I was ALWAYS able to charge between 8 and 9 AM, but never after 10pm.

Now, except when reducing amps, I can’t charge anytime.

No AC issues here, since it’s not hot, not cold regionally. No industry around to explain uneven (dirty) power delivery.

Sounds like the software is more sensitive here. Too many people having the same issue with no previous issues before. For me the place at which we charge and time makes a difference (using the same car and the same charger).

 

[mylesm260]

Update for today:

I had friends over to watch a particular event on TV (let's not touch on politics here) and he brought over his pocket scope.

it was 8:30 pm by the time I used the scope on my power and tried to plug my car in... and, as is the case with trying to diagnose most issues, the damn thing worked just fine (see attached)

I will try again tomorrow closer to 6pm my time. hopefully then it will fail so I can produce some better data. Regardless, this should act as a "baseline" for me. Charging started ( >3 amps) within 15-20 seconds of plugging in.

To my eye, the sine wave shown on the scope looks relatively clean, the curve at the top / bottom is somewhat imperfect, but still looks pretty good. Stay tuned.

 

[MOMedic82]

I'm landing on software being the culprit. Looks like most of us started having issues at about the same time. Hard to explain it with anything else since we have different cars and are in different parts of the country.

My vehicle has been charging fine for the last bit.... After I got the last update.

 

[pacopico]

Similar problem here.

2020 Model 3 Performance with 19K miles.

I have a Grizzl-E 40A EVSE (J1772 with OEM Tesla Adapter) on a NEMA 14-50R circuit, 6AWG THHN wire about 1.5' total wiring run length from the breaker panel which is GE 200A service, the EVSE breaker is in the first breaker bay closest to the main feed. 2005 built house and panel.

Idle voltage is 245, full load at 40A is 239-240.

Lately I have noticed that the car was only charging at 32A, and the display showed 32/40 meaning that it was seeing the signal from the EVSE that 40A was available.

A couple times I removed the plug and reinserted and it took about a minute to get back up to 32A and would not go any higher. I could see the car was seeing the available voltage and amperage limit immediately after plug in and initialization, and it would sometimes take 30 seconds bouncing between 0-2A before it started actually charging.

A couple other times when re-plugging in it would initialize and after 10 seconds or so start walking up the amps all the way to 40A as I would consider normal.

I have found that if I stop and restart the charging from the app it will usually (90% of the time) reconnect and go to 40A.

I don't know exactly when this started other than within the last month or so.

I did check last night that all connections are tight and there are no signs of heat or arcing at the connections and found all was OK.

 

[jim_p]

After charging fine since Saturday, I got an error this morning with around 5 minutes left on a scheduled charge. Unlike what others have stated, it appears in my area, as the weather cools down, I think I'm seeing voltage increases that are keeping the car from charging. Hard to tell since it's usually between 243-245V. Was hoping I was past the issue, obviously not yet.

 

[RheesB]

We put a old scope out of the barn on it and were not surprised. Our grid power looks like a typical sine wave, proper frequency, voltage and pretty clean. My old generator had a bit of noise from the rectifiers and such but cleaned up under 22A load.
Scope vertical would not cal so you get what you see,
One of generator unloaded, one loaded and one utility power.
Our service guy says there are plenty of folks with the issue and multiple engineers are on this.
He also says one customer seems to have had some luck with a whole house surge protector. I ordered one.
Meanwhile, after all the generator running we have a bunch of miles! Gotta go get new snow tires. The hawk is near.

 

[CoachK]

After charging fine since Saturday, I got an error this morning with around 5 minutes left on a scheduled charge. Unlike what others have stated, it appears in my area, as the weather cools down, I think I'm seeing voltage increases that are keeping the car from charging. Hard to tell since it's usually between 243-245V. Was hoping I was past the issue, obviously not yet.

Had a similar experience. Over the weekend I was able to get both M3 and MY to 48 amps. Today it’s back to 0-2 amps with 246-247 V and it’s gotten cooler since the weekend.

 

[mylesm260]

Update,

Plugged in today, I could tell right away it was going to fail... 0/1/2 amps for the first 2 minutes.. so I connected my scope right away, and the sine wave definitely looked less perfect than the past 2 days when the car charged perfectly. (atached)

I talked to a friend of mine who had done some research on this as well... the issue may be that the onboard chargers in these teslas are under-engineered. basically, slightly dirty power could be causing premature failures. And the reason for the software update that caused this issue in the first place could be in fact to reduce the number of onboard AC charger failures.

At the end of the day, the onboard AC charger is just an AC to DC converter, albeit a very efficient and precise one. But our homes are full of devices that are also AC to DC converters and work with dirty power perfectly fine. A PC power supply, for example, can produce 750 watts (As an example, depending on the model) with high efficiency, and they rarely fail and never have issues with "slightly dirty" power.

Granted the onboard chargers are dealing with much more energy than a PC power supply, but the general principals are the same. Tesla may be trying to mask a greater problem with their on-board AC chargers.... This theory would also explain why they didn't simply "go back" to the previous software configuration once this issue became obvious.

 

[pjensen]

Update,

I talked to a friend of mine who had done some research on this as well... the issue may be that the onboard chargers in these teslas are under-engineered. basically, slightly dirty power could be causing premature failures. And the reason for the software update that caused this issue in the first place could be in fact to reduce the number of onboard AC charger failures.

Agree completely.

Looking at that sine wave, it appears to have a high frequency component in it (with a fair amount of power). I wonder if this is causing an issue with the computer chip that controls the charging power supply. The chip goes nuts and destroys the power devices - or just fails to work. Possibly it has inadequate filtering of the incoming voltage. That would require a hardware fix. Software won't be able to solve it.

If you have access to a FFT scope, it could show the frequency of that sharp edge sine wave.

 

[jim_p]

Had a similar experience. Over the weekend I was able to get both M3 and MY to 48 amps. Today it’s back to 0-2 amps with 246-247 V and it’s gotten cooler since the weekend.

I was also at 246-247 last night and charging failed, this morning at 244v it charged at a reduced rate (16/32A). I already have a home surge suppressor and that appears to not provide any change.

I'll ask a silly question, does anyone know if there is a reasonable way to regulate/condition the voltage on the house side as it appears over 244/245 is not well tolerated? since 1) it appears to not be a simple software fix or it would have been done already and 2) I hold out little hope that I could actually get the utility to do anything about it.

 

[mylesm260]

I was also at 246-247 last night and charging failed, this morning at 244v it charged at a reduced rate (16/32A). I already have a home surge suppressor and that appears to not provide any change.

I'll ask a silly question, does anyone know if there is a reasonable way to regulate/condition the voltage on the house side as it appears over 244/245 is not well tolerated? since 1) it appears to not be a simple software fix or it would have been done already and 2) I hold out little hope that I could actually get the utility to do anything about it.

The voltage itself isn't really that relevant. If there is significant voltage drop, the charging will be reduced (lower amps) but other than that I don't believe voltage is the issue here. If it's within the acceptable range, which is likely something like 240 +/- 5% unloaded, voltage should not be an issue.

If you consider that 208 is also an acceptable voltage, the +/- may be even greater that 5%.

In terms of a way to "fix" the sine wave...

As far as I know fixing the sine wave is very hard / not practically possible. You can "reproduce" the sine wave, either mechanically by having a motor drive a generator, or electronically by having an AC to AC inverter (some modern microwave ovens use this technology). But here's the thing....

We shouldn't have to. While some of our sine waves DO look somewhat imperfect, our Teslas are the ONLY things not able to cope with it.

Is anyone else who is having charging issues experiencing any issues with any of the dozens of other electrical / electronic devices in their homes?

It's becoming clear that there is a fundamental design / manufacturing deficiency with these onboard AC chargers. They are prone to failure, and the engineers are trying to mitigate the failures with software updates. That's why all of us were able to charge perfectly, and then one day, some time immediately after the software update, we started having issues.

Now the question is, will their engineers be able to come up with some kind of "compromise" software update that will allow those of us with *slightly imperfect* sine waves to charge, even at a reduced rate, or will resolving this require physical changes, like swapping out the physical onboard AC chargers.

Think about this: Computer Servers are generally plugged into Uninterruptable power supplies: basically a battery backup for the server for when the power goes out.

Computer servers are about as mission critical, "sensitive to dirty power" as you can get. If you ever looked at the sine wave coming off a typical server grade UPS, it looks like HOT GARBAGE compared to the sine waves that are causing our tesla's not to charge.


We need to all be aware of this to make sure we keep the pressure on Tesla to resolve this issue. The last thing we want, is to all be experiencing on board AC charger failures just after our warranties expire.

The onboard chargers should be able to take a slightly imperfect sine wave in stride, no questions asked: literally every other electric / electronic device you can think of already can.

 

[mylesm260]

He also says one customer seems to have had some luck with a whole house surge protector. I ordered one.

Household surge protectors work by adding a metal oxide varistor in parallel with the load. These are a consumable and only last for a limited amount of time. This is why surge protectors have lights on them to tell if you if they are working or not. After a few short years, most surge protectors lose their ability to protect, and just end up being glorified power bars.

I don't think a metal oxide varistor will have any effect here. This issue is not "momentary peaks" being "over the acceptable range" on input voltage, this issue is "imperfect" sine waves.

Basically, it isn't a surge causing the issue, it's dirty power causing the issue.

I believe the software issue that caused this is "analyzing" the power coming in, and if the power coming in looks too "dirty" then it just refuses to charge, so it doesn't run the risk of damaging the overly fragile onboard AC charger.

I honestly don't think a surge protector will have any effect... but I could be wrong.

 

[Sans-gas]

I’ve noticed no similar problems reported by non-US owners. I wonder if this may help narrow down the software issue for Tesla.

 

[mylesm260]

I’ve noticed no similar problems reported by non-US owners. I wonder if this may help narrow down the software issue for Tesla.

I'm Canadian. I definitely have the issue.

 

[Sans-gas]

I'm Canadian. I definitely have the issue.

Sorrry, yes. I should have said non-North American.

 

[MOMedic82]

After a short time of no issues.... I am back to the same problem today.

 

[RheesB]

Looking at the waveform (shown in previous message) on my utility and that on my generator makes me laugh. The utility is giving what you would expect but the car will not charge on 120V or 240V. My old generator with lots of noise charges the car at 240V 24A just fine. ???

 

[MOMedic82]

I'm back on the phone with tesla getting escalated to yet a higher level....

 

[MOMedic82]

Okay, I manged to speak with a 2nd level supervisor at the Tesla Customer Support Center and got some better information.

It seems when he gets pretty deep into the diagnostics, there are some errors popping that are not visible to end users and "might be easy to miss" if the SC techs are convinced it's a home issue and don't dig very deep.

He went ahead and scheduled a Ranger service appointment for me from his end, and attached all the errors/diagnostics that he can see. He said that this should result in a replacement of the onboard charger. He stated that in his experience there are some onboard chargers that just get temperamental and due to this won't draw the load. This is why the car shows the available amperage but won't pull it. He made it seem that if the car is showing "XX/32a" on the charge screen, then it's not an issue on the house side as the charging system has verified the availability of the line/charger setup.

I strongly got the impression he has seen this before and his statements weren't guesses.

I would suggest to all having this issue, call the customer service line, get on with a supervisor and have them do full diagnostics and look for the precharge error.