Charge speed setting glitch?

[rockinshoe]

I have a 50 amp circuit feeding my Tesla wall connector which is set at 50 amps. I have set the speed on my new MY and the app to charge at 40amps. After my first overnight charge I noticed the app was showing 48 amps. I reset the charge to 40amps and went about my day. I wrote it off as a mistake somewhere on my part, but the same thing happened again the next day, and the next.
I’m assuming that the actual charge is being delivered at 40 amps because we haven’t had the lights go out yet. I guess it wouldn’t be a huge problem to check the settings every time I charge, but I was assuming this was a one-and-done.
Has anyone else had a similar problem?

 

[Sophias_dad]

Your wall connector is commissioned incorrectly. The display in the car should be reading 40/40 amps, and you shouldn't need to manually set it down to 40 from 48.

 

[jcanoe]

Your wall connector is commissioned incorrectly. The display in the car should be reading 40/40 amps, and you shouldn't need to manually set it down to 40 from 48.

It appears from the OP's post that their Wall Connector is correctly commissioned. For a 50 amp circuit you set the Wall Connector to the 50 amp setting, the Wall Connector automatically limits charging to 40 amps (80% of 50.) The OP stated that the Tesla app showed a charging amperage of 48 amps after the overnight charging session had completed, not while actively charging. The OP did not attach a screen image of the Tesla app or charging screen so we don't have confirmation that the screen showed the charging amperage while charging as 48/48 or 40/40 or something else.

The Tesla Model Y should remember the previous charging amperage setting for your home, work or other locations. Sometimes the Tesla vehicle forgets the previous charging amperage setting for the location and will default to 48 amps. If the Tesla vehicle defaults to 48 amp charging this will not enable the Tesla vehicle to begin charging at 48 amps. The Wall Connector is always the final arbiter in the handshake negotiation between the Tesla vehicle and the Wall Connector. When the Wall Connector is set for use on a 50 amp circuit the Wall Connector will limit the charging amperage to 40 amps.

The OP should verify that they have set their Home location in the Tesla Navigation system. Even then, sometimes the Tesla app will display the default charging amperage setting of 48 amps (but not while actively charging.)

 

[E90alex]

When and where are you checking? The car defaults to displaying 48 amps when unplugged and it remembers that setting based on location. That doesn’t mean it will try to pull 48 amps if the EVSE is not capable of it. When unplugged it will show 48 amps but once plugged in it will show whatever the EVSE max is.

If it’s showing 48 amps when plugged into your wall connector then the wall connector is not set up properly.

 

[rockinshoe]

Your wall connector is commissioned incorrectly. The display in the car should be reading 40/40 amps, and you shouldn't need to manually set it down to 40 from 48.

The choices on my connector ask for the breaker size — which is 50amps, so I checked the box marked 50amps.

 

[rockinshoe]

When and where are you checking? The car defaults to displaying 48 amps when unplugged and it remembers that setting based on location. That doesn’t mean it will try to pull 48 amps if the EVSE is not capable of it. When unplugged it will show 48 amps but once plugged in it will show whatever the EVSE max is.

If it’s showing 48 amps when plugged into your wall connector then the wall connector is not set up properly.

I am charging at home. I double checked the wall charger and it is set for 50amps. I have set the app before I go to bed to 40 A, it charges and doesn’t trip the breaker, yet when I look at the app in the morning it is back to 48A

 

[Sophias_dad]

I am charging at home. I double checked the wall charger and it is set for 50amps. I have set the app before I go to bed to 40 A, it charges and doesn’t trip the breaker, yet when I look at the app in the morning it is back to 48A

Can you get a screen shot of your commissioning screen? I assume we are discussing a Tesla Gen 3 HPWC here...

Not that I don't believe you, but there have been tens or hundreds of thousands of these installed and I'm pretty sure they(the cars connected to them) display the max charge rate the HPWC is declaring on the right side of X/Y amps, whether actively charging or not.

 

[rockinshoe]

Can you get a screen shot of your commissioning screen? I assume we are discussing a Tesla Gen 3 HPWC here...

Not that I don't believe you, but there have been tens or hundreds of thousands of these installed and they(the cars connected to them) display the max charge rate the HPWC is declaring on the right side of X/Y amps.

Sorry if I left this out: it is a model Y.

Can you get a screen shot of your commissioning screen? I assume we are discussing a Tesla Gen 3 HPWC here...

Not that I don't believe you, but there have been tens or hundreds of thousands of these installed and I'm pretty sure they(the cars connected to them) display the max charge rate the HPWC is declaring on the right side of X/Y amps, whether actively charging or not.

 

[rockinshoe]

I did not know if the connector would limit the charge to 40A. If that’s the case. I’m not worried at all

 

[Sophias_dad]

I did not know if the connector would limit the charge to 40A. If that’s the case. I’m not worried at all

The connector tells the car how much it can take. Its up the the car to take only that much.

Can you get a screenshot of the Y's screen when its reading 48A? Maybe @jcanoe is correct that if its not drawing power the screen shows 0/48A. I'd find that super strange.

I just turned my Gen2 HPWC down to 40A and its showing 0/40A when I stop charging. It also says "Max charge rate at this location: 40A" on the charging screen(which it changed automatically when I plugged the HPWC into it).

 

[jcanoe]

I just opened the Tesla app on my phone. My Model Y is parked, not plugged in. The charging screen display shows:

Charging limit: 90% (I rarely charge above ~80% (85% in winter). I manually stop charging when I am ready to leave the garage where I park, charge most days (always for less than 2 hours.)
6kWh added during last charging session
(below that is the charging slider control)
(below the charging limit slider is the charging rate limit)
< 48 A (even though the last charging session (not at home was 30 A) and when at home I charge at 32 A. (No matter how many times I reset this to 30 A or 32 A the charging amperage setting eventually return to 48 A.)

If I plug in my Model Y is set to begin charging immediately. At home when plugged in and charging my Model Y will display 7kW, 32/32, ~233V

 

[rockinshoe]

I just opened the Tesla app on my phone. My Model Y is parked, not plugged in. The charging screen display shows:

Charging limit: 90% (I rarely charge above ~80% (85% in winter). I manually stop charging when I am ready to leave the garage where I park, charge most days (always for less than 2 hours.)
6kWh added during last charging session
(below that is the charging slider control)
(below the charging limit slider is the charging rate limit)
< 48 A (even though the last charging session (not at home was 30 A) and when at home I charge at 32 A. (No matter how many times I reset this to 30 A or 32 A the charging amperage setting eventually return to 48 A.)

If I plug in my Model Y is set to begin charging immediately. At home when plugged in and charging my Model Y will display 7kW, 32/32, ~233V

Well, at least I’m not delusional

 

[rockinshoe]

As long as there isn’t a problem not having agreement between the charger at 40A and the car at 48A, it shouldn’t be a problem for me. I just don’t want to feel that I always have to check the app (or the screen) before I charge.

 

[Rocky_H]

@rockinshoe I've seen a lot of threads on this same issue with new owners in a panic, and it's just a confusion in the way you're asking it that is throwing people off. You never said that you SEE it charging at 48A. You just said that you saw it showing 48A when it is NOT charging. People see the 48A showing when the car is not charging, and they think the car is going to overdraw their circuit and do something dangerous.

But that is just the default thing the car shows when it is not connected. It will show you the max capability of the onboard charger built into the car. That is 48A.

But when you plug it into charging equipment, they communicate. Your wall connector is correctly announcing to the car that 40A is all is has available. So then the car will not ask for more than 40A. This is all working exactly as it should.

 

[rockinshoe]

@rockinshoe I've seen a lot of threads on this same issue with new owners in a panic, and it's just a confusion in the way you're asking it that is throwing people off. You never said that you SEE it charging at 48A. You just said that you saw it showing 48A when it is NOT charging. People see the 48A showing when the car is not charging, and they think the car is going to overdraw their circuit and do something dangerous.

But that is just the default thing the car shows when it is not connected. It will show you the max capability of the onboard charger built into the car. That is 48A.

But when you plug it into charging equipment, they communicate. Your wall connector is correctly announcing to the car that 40A is all is has available. So then the car will not ask for more than 40A. This is all working exactly as it should.

I said I was all set, everything is good

 

[EVCT]

I just opened the Tesla app on my phone. My Model Y is parked, not plugged in. The charging screen display shows:

Charging limit: 90% (I rarely charge above ~80% (85% in winter). I manually stop charging when I am ready to leave the garage where I park, charge most days (always for less than 2 hours.)
6kWh added during last charging session
(below that is the charging slider control)
(below the charging limit slider is the charging rate limit)
< 48 A (even though the last charging session (not at home was 30 A) and when at home I charge at 32 A. (No matter how many times I reset this to 30 A or 32 A the charging amperage setting eventually return to 48 A.)

If I plug in my Model Y is set to begin charging immediately. At home when plugged in and charging my Model Y will display 7kW, 32/32, ~233V

You say you charge at home at 32 A. Is there a benefit as far as the battery goes to using that number or is 32A the most your charger can put out.

Thanks….

 

[jcanoe]

You say you charge at home at 32 A. Is there a benefit as far as the battery goes to using that number or is 32A the most your charger can put out.

Thanks….

32 amps is the maximum supported by the EVSE I purchased. 32 amps is also the maximum supported amperage of the Tesla Mobile Connector when used with the Tesla NEMA 14-50 power plug adapter (also NEMA 6-50 power plug adapter).

40 amps is the maximum charging amperage for the 50 amp circuit that my electrician installed but I did not need to charge any faster than the up to 29 miles of range that can be added to the battery of my Tesla Long Range Model Y when charging at 32 amps.

32 amps slots right in the middle of three of the common 240V charging amperage rates, 16/32/48, with 24 amp and 40 amp charging rates also being available, depending on the circuit rating.

 

[EVCT]

32 amps is the maximum supported by the EVSE I purchased. 32 amps is also the maximum supported amperage of the Tesla Mobile Connector when used with the Tesla NEMA 14-50 power plug adapter (also NEMA 6-50 power plug adapter).

40 amps is the maximum charging amperage for the 50 amp circuit that my electrician installed but I did not need to charge any faster than the up to 29 miles of range that can be added to the battery of my Tesla Long Range Model Y when charging at 32 amps.

32 amps slots right in the middle of three of the common 240V charging amperage rates, 16/32/48, with 24 amp and 40 amp charging rates also being available, depending on the circuit rating.

Ok…thanks…