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Gen 2 Wall Charger Now Only Goes to 16 Amps

Quorky

Member
Oct 1, 2019
334
196
NYC
Based on all the above it must be some kind of software issue. I'm installing the 2020.36.11 update right now to see if that does something. Otherwise, the only thing I can think of is that it's some kind of software issue. If I could get someone to plug their Tesla into my charger and have it work I could rule out the charger. But based on the fact that the same thing happened with the mobile charger, I'm pretty sure it's fine.

Have the new software installed. Problem seems to persist. It seems Tesla is hot pushing 36.12 to the Y (via cell) could be rolling out a hot fix for this in waves but let's see. In the last day we have seen 10ppl post same issue in the M3 threads. It feels like a software bug with so many suddenly experiencing the same issue.
 

RedNeB

Member
Jun 3, 2019
45
18
CT
We are still dealing with it. We are trying to isolate where the issue lies. It can’t be the Wall Connector alone since the two mobile chargers we have are not working either but yet worked when we took them to Tesla Service (we assume that since they are in a Commercial site there power flow ( volts) are more steady. We had the house checked by an electrician and all the readings of power inflow (volts) coming in were 240+. The wall charger too showed 240 coming in. We manually increased the amp setting in the car while charging as a previous user posted. It’s set at 38amps and yet we are charging at 12-16 amp with 244 volts. In other threads someone seemed to think it might be caused by the software update and adjusting something with fluctuating volts making it more sensitive. We called someone we know at the local Tesla. They escalated and we shared that it seems to be happening to others based on the posts here.

It’s one of those circular conversations - Tesla says it’s the house, the electrician says its the car and the power company is MIA on our inquiry.

You did what I was going to do, but figured the electrician would charge me $150 to tell me it's the car or charger's problem. If the 18 ft. Gen 3 chargers were in stock today, I probably would have bought one since I was convinced that would fix it. Maybe it wouldn't.
 

RedNeB

Member
Jun 3, 2019
45
18
CT
Have the new software installed. Problem seems to persist. It seems Tesla is hot pushing 36.12 to the Y (via cell) could be rolling out a hot fix for this in waves but let's see. In the last day we have seen 10ppl post same issue in the M3 threads. It feels like a software bug with so many suddenly experiencing the same issue.

I think you're right. Fortunately we live a couple minutes from a super charger and a few other free destination chargers if all else fails. Hopefully Tesla pushes something through quickly as I was so spoiled with the 44 mph speeds. Funny how spoiled I've gotten since I survived the first 3 months with 4 mph on the trickle charger in the wall socket.
 

Quorky

Member
Oct 1, 2019
334
196
NYC
I think you're right. Fortunately we live a couple minutes from a super charger and a few other free destination chargers if all else fails. Hopefully Tesla pushes something through quickly as I was so spoiled with the 44 mph speeds. Funny how spoiled I've gotten since I survived the first 3 months with 4 mph on the trickle charger in the wall socket.

Honestly it's not a big deal. I went from charging at 30mph every 4 days to 14mph every other day or so. Just keep it topped off and not a big deal. Just hope this doesn't persist for longer than a few weeks.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
8,900
9,917
Riverside Co. CA
You did what I was going to do, but figured the electrician would charge me $150 to tell me it's the car or charger's problem. If the 18 ft. Gen 3 chargers were in stock today, I probably would have bought one since I was convinced that would fix it. Maybe it wouldn't.

Those Gen 3 wall connectors have been having a lot of issues. I personally wouldnt trade my gen 2 for a gen 3 at this point. Those have been having all sorts of issues reporting overheating, etc.
 
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AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
9,775
11,746
San Diego
. Only explanation for that one is that your home circuit has suddenly developed wild voltage swings

I think it's more likely that a software update made the CAR more sensitive to some sort of wiring issue (it's looking at something more carefully/has tighter parameters on what it will tolerate), or some other issue that varies between cars.

I can't think of another explanation for this issue and a similar issue in the other thread (though they seem to be somewhat different).

The only fly in the ointment is that there is one report in the other thread that is not coincident with a software update (the problem allegedly first occurred BEFORE a software update).

It would be interesting to see pictures from people of their grounding situation for their charging setups (at the outlet, at the subpanel if applicable, and at the main panel). For setups which work, and setups that don't.

It's not the UMC or WC checking the ground continuity (they already do that) that is causing problems, it seems to be car-related...

It could also be the software update is finding issues (variation) between CARS + WIRING that is causing problems (it's entirely possible there are small variations in the charger circuitry in the car and the software may not be compatible/properly tested on all such variation). The way to rule this out is to have someone with an "ok" Model 3 come over to one of the "problem houses" and try the charging setup. It's presumably not just the variability in the car itself ALONE that is the issue, otherwise the car would not charge elsewhere (in general they seem to work fine elsewhere).

This is the other thread I am referring to: Charging Issue Level 2 at Home
 

RedNeB

Member
Jun 3, 2019
45
18
CT
I think it's more likely that a software update made the CAR more sensitive to some sort of wiring issue (it's looking at something more carefully/has tighter parameters on what it will tolerate), or some other issue that varies between cars.

I can't think of another explanation for this issue and a similar issue in the other thread (though they seem to be somewhat different).

The only fly in the ointment is that there is one report in the other thread that is not coincident with a software update (the problem allegedly first occurred BEFORE a software update).

It would be interesting to see pictures from people of their grounding situation for their charging setups (at the outlet, at the subpanel if applicable, and at the main panel). For setups which work, and setups that don't.

It's not the UMC or WC checking the ground continuity (they already do that) that is causing problems, it seems to be car-related...

It could also be the software update is finding issues (variation) between CARS + WIRING that is causing problems (it's entirely possible there are small variations in the charger circuitry in the car and the software may not be compatible/properly tested on all such variation). The way to rule this out is to have someone with an "ok" Model 3 come over to one of the "problem houses" and try the charging setup. It's presumably not just the variability in the car itself ALONE that is the issue, otherwise the car would not charge elsewhere (in general they seem to work fine elsewhere).

This is the other thread I am referring to: Charging Issue Level 2 at Home
Yeah, very strange. In my instance, the issue doesn't seem to be tied to any event - didn't happen after installing an update, I didn't have any work on any of the electrical systems in my house. What's really strange is the distination charger I went to (not sure if it's a Gen 1 or Gen 2 version) hd no problems charging at 48 amps. Something very strange going on.

Here's my panel pic for any interested. Pretty standard as far as I can tell. Tesla charger breaker circled.
20200923_225651.jpg
 

CoachK

Member
May 5, 2019
21
12
Philadelphia
Has anyone here tried:

1. Turn off the wall connector breaker
2. Making sure power is off (no light).
3. Taking cover of wall connector off.
4. Tighten down the screws for the incoming electrical wires.

The wall connector could very well be reading a loose connection. It has sophisticated software algorithms to detect that.

We did ask the electrician to do that - tightened all the screws and connections and nothing changed, The fact that the mobile chargers do not work leads me to believe it's not the Wall Charger so we have ruled that out. It's either the power coming in at the fuse box or a change to the car. The electrician checked the fuse box and all connections and grounding were as they should be.

We are leaning more towards the car since there are several similar incidence happening roughly at the same time across the country.
 

RedNeB

Member
Jun 3, 2019
45
18
CT
Things make even less sense today - plugged it in and everything is working like normal. Strangest thing I've seen. We didn't do anything differently. Wonder if it was just a temporary glitch or if this is just a temporary fix. Glad it appears to be working as designed now.
 

CoachK

Member
May 5, 2019
21
12
Philadelphia
Things make even less sense today - plugged it in and everything is working like normal. Strangest thing I've seen. We didn't do anything differently. Wonder if it was just a temporary glitch or if this is just a temporary fix. Glad it appears to be working as designed now.
That’s great. Glad it’s working. We unfortunately are still at 16A with 242V.
 

RedNeB

Member
Jun 3, 2019
45
18
CT
You said it also failed on a neighbors outlet, but worked on a WC some distance away?

Very strange.
I never tried it on a neighbors - that may have been someone else in the thread. I went to a destination charger, which had the same type of HPWC and it worked fine with no problems. I'm stumped, but glad it's working. We'll see if it stays that way.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
6,271
7,334
Boise, ID
I've looked in on this thread a couple of times, and just realized no one has given what is probably the answer to this. Sorry it took me this long to realize that and respond here. @CoachK and @RedNeB , the 16A limit is the clear indicator of what the problem is.

The onboard chargers in the cars are built from internal modules of 16A each. The smaller battery cars that have a max charging limit of 32A have two of these internal boards populated inside the charger, and the larger cars with the 48A onboard chargers have three of them inside.

I've seen several threads here on this forum where someone's 32A charging mysteriously drops to 16A or the 48A mysteriously drops to 32A, where one of the internal modules failed, but the car overall handles it gracefully, by still running on what is left functioning in the charger, minus the part that failed.

The cars really should have a better way of monitoring and displaying a specific error, explaining the problem when this happens, but so far they don't, and we just have to recognize it by the increment of a 16 amp reduction in charging power.
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
9,775
11,746
San Diego
I've looked in on this thread a couple of times, and just realized no one has given what is probably the answer to this. Sorry it took me this long to realize that and respond here. @CoachK and @RedNeB , the 16A limit is the clear indicator of what the problem is.

The onboard chargers in the cars are built from internal modules of 16A each. The smaller battery cars that have a max charging limit of 32A have two of these internal boards populated inside the charger, and the larger cars with the 48A onboard chargers have three of them inside.

I've seen several threads here on this forum where someone's 32A charging mysteriously drops to 16A or the 48A mysteriously drops to 32A, where one of the internal modules failed, but the car overall handles it gracefully, by still running on what is left functioning in the charger, minus the part that failed.

The cars really should have a better way of monitoring and displaying a specific error, explaining the problem when this happens, but so far they don't, and we just have to recognize it by the increment of a 16 amp reduction in charging power.

The thing is that the car charges fine elsewhere (and this is common to the issue in the other thread too). So it rules out the charger quantization. Though it may suggest that a couple of the chargers are not making the car happy for some reason, when powered by an external AC source that somehow is deficient. On some cars apparently it's 3 out of 3 chargers.

Just a guess though. I've given up on figuring out what this problem is.

See:
went to a local HPWC destination charger and had no issues there
 

CoachK

Member
May 5, 2019
21
12
Philadelphia
I've looked in on this thread a couple of times, and just realized no one has given what is probably the answer to this. Sorry it took me this long to realize that and respond here. @CoachK and @RedNeB , the 16A limit is the clear indicator of what the problem is.

The onboard chargers in the cars are built from internal modules of 16A each. The smaller battery cars that have a max charging limit of 32A have two of these internal boards populated inside the charger, and the larger cars with the 48A onboard chargers have three of them inside.

I've seen several threads here on this forum where someone's 32A charging mysteriously drops to 16A or the 48A mysteriously drops to 32A, where one of the internal modules failed, but the car overall handles it gracefully, by still running on what is left functioning in the charger, minus the part that failed.

The cars really should have a better way of monitoring and displaying a specific error, explaining the problem when this happens, but so far they don't, and we just have to recognize it by the increment of a 16 amp reduction in charging power.

Thank for this. What’s not clear to me is that this happened all at once to both the 2019 M3 LR and the 2020 MY LR. What are the odds that both internal modules fail at the same time on two different vehicles? The cars do charge on a Super Charger and destination charger which may be more related to AC delivery so no factor.

One option is to go to a friends home and try their wall charger. They said there car is charging. If it works then it’s not an internal module issue but something else e.g. software or charge flow fluctuation - does that make sense?
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
9,775
11,746
San Diego
destination charger which may be more related to AC delivery so no factor.

Destination chargers (of the HPWC variety) are AC chargers, just like the home. They're often at ~208V or whatever though (commercial voltages).

You should definitely try it at a friend's. I suspect it will work. I also doubt it is anything *wrong* with your wiring in the house. But I could be wrong about that (for a while I thought it was an issue with house wiring).

I think it's software not playing well with some specific combinations of the in-car AC-DC chargers and the AC source. But that's not 100% supported by the timing wrt software updates, at least based on users' reports, so who knows.

I guess we'll find out eventually.
 
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RedNeB

Member
Jun 3, 2019
45
18
CT
Update from me - mine still doesn't work. Charging now at 16 amps again. I hate to blame it on my wife, but she was the one who told me it was working fine this afternoon. I'll chalk it up to her misreading things on the display.
 

pjensen

Member
Jul 24, 2020
155
93
Highland Village, Texas
Update from me - mine still doesn't work. Charging now at 16 amps again.

Are there any nearby transmitters (ham, cb) in your neighborhood?

Strong, nearby transmitters can cause radio frequency interference (RFI) in computer circuits - and drive them nuts. And it will be random - only when that transmitter is being operated on a particular frequency.
 
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